Speech and Language Development Midterm

Communication

The process by which messages or information are sent from one place or person to another OR the message itself. Includes linguistic and extralinguistic elements

Language

A system of communication consisting of sounds, words, and grammar, shared by a group of people.

- Defined as: Code + System + Arbitrary Signals

Speech

The ability to use the vocal apparatus to generate spoken language. Involves verbal communication through articulation (aka NOT sign language)

Phonetics

Individual speech sounds

Phonology

how sounds are organized and combined in a language

Morphology

words and the rules that govern word formation

Syntax

Sentence structure and word order

Semantics

Meaning

Pragmatics

How language is used in context

Key Properties of language

1. Arbitrary - form of word has arbitrary relation with meaning of the word

2. Rule - Governed - word order violations, subject-verb agreement, ways to combine affixes and roots, and pluralizations (z/s)

3. Generative / Creative: recursion (ability to embed or repeat structures within sentences), nesting (adding elements to the left or right of the verb. With a finite set of elements we can express an infinite amount of ideas.

4. Untaught

What do we know when we know a language

1. Content (Semantics - Meaning)

2. Form (anything that has to do with rules) - phonology, morphology, and syntax

3. Use (pragmatics - language use in context)

Competence

Inner, unconscious knowledge of the rules of language

Performance

expressions of the rules in everyday speech - our actual use

Prescriptive Grammar

Specify how a language and its grammar rules should be used

Descriptive Grammar

Describe how people use language in daily life including standard and nonstandard varieties - very steady, how native speakers actually speak.

Animal Communication

- Cuckoo song learned no matter environment

- Sparrow learns aspects of songs no matter environment

- Bee dance, parrot speech

- lots of variety

- Unlike human communication - fewer forms to express limited content for limited uses combined in limited ways. Even in primates who show linguistic ability, skills do not surpass those of a 3 year old. And animals need explicit instruction unlike humans.

Types of Communication

1. Extralinguistic (outside): anything that adds emotion, prosody. Includes paralinguistic, nonlinguistic (gestures, body language), metalinguistic

2. Linguistic: speaking and listening, writing and reading, signing

Properties of Human Language

1. discrete elements that we can combine

2. big vocabulary (10,000 - 100,000 words)

3. Displaced reference - can talk about things that are not present (future, past, hypothetical)

4. Productivity - language is generative, productivity comes from syntax, morphology and recursion

5. Culturally transmitted - children learn specific language of community

6. Species specific - only humans naturally acquire full language

7. Species uniform - no human group lacks language.

Spontaneous Conversational Sampling or Natural Observation

- Observe what the child is doing in naturalistic setting, dont change or control any variables.

1. Diary - researcher or participant record linguistics events.

- Pro: rich in qualitative and longitudinal data

- Con: memory limitations, unintentional bias, time and effort consuming, validity and reliability not clear

2. Checklists - lists of words/utterances/milestones that a child should reach

- Pro: normed data, low cost, time efficient, comprehension and production, early age

- Cons: bias, limited number of pre-determined items

3. Language Sample - recording device for children and analyze what they say

- pro: naturalistic and ecologically valid

- con: time consuming and labor intensive

Structured Testing or experimental manipulation

specific variables that experimenters are interested in collecting

1. Habituation - the habituation is the regression in response of an organism to a repeated stimulus. Results in physiological response such as a change in heartbeat rate, a change in sucking rate, or an orienting behavior such as increased fixation

- Pro: no reliance on overt response

- Con: ambiguous results, high attrition rates, requires high sensitivity

2. Conditioned head turn - requires conditioning of the infant with a reward upon performing a head turn when hearing a new stimulus.

- Pro: multiple trials, linking stimulus and response

- Con: cant use under 6 months of age, additional task demands.

3. Preferential Looking: uses eye-tracking. Participant presented with 2+ stimuli and their gaze pattern is collected. If they show behavioral differences between stimuli, they have sensitivity to difference between stimuli

- Pros: natural response, cross modal

- Cons: limited information (know where but not why), difficulty with young infant, observer bias

4. Neuroimaging: MEG, ERP, fMRI, fNIRS,

- Pro: reveal biological mechanisms that underlie cognitive capacities

- Con: expensive, infants are hard to be still

Structuralism

- language is a system of internal structures, rules exist independently of use, and grammar can be studied in isolation

- focuses on syntax, morphology, formal rules and competence (mental knowledge)

- care about word order, movement rules, hierarchical structure rather than who is speaking, why and social context

Functionalism

- Language is a tool used on context. Language exists to communication, structure is shaped by function and context, grammar emerges from use over time

- Focuses on meaning, pragmatics, discourse, social interaction, and performance (actual language use)

- Cares about speakers intentions, listener knowledge, social rules

Nativism

- Language is too complex to be learnt in such a short period through imitation only

- Humans are born with language specific knowledge (speed, uniformity and creativity of speech proves this point)

- Universal grammar, poverty of stimulus, language acquisition device (mental mechanism for extracting grammar)

- emphasizes syntax, competence, structural mechanisms

- CHOMSKY

Empiricism

- Focuses on the influence of the environment and social interaction on language acquisition

- language is learned entirely through sensory experience, social interaction, and environmental input, rather than being innate

- tabula rasa: the mind begins as a blank slate and language is learned through experience with the environment

- rich input from caregivers, social scaffolding, general learning mechanisms (pattern detection, memory, attention

- emphasize environment, social interaction, pragmatics and performance

B.F. Skinner's Behaviorism

- language is learned in the same way as any other behavior, through imitation, reinforcement and conditioning (children dont know grammar, they learn patterns that are rewarded)

- classical conditioning

- operant conditioning

- Grammatical frame and substitution: a grammatical frame is a partially fixed sentence pattern that a child learns as a chunk through imitation + reinforcement. Once frame is learned, child is thought to swap in different words based on experience, strengthening the habit and acquiring productivity

- each word acts as a stimulus for the next word

- this theory fell out of favor bc: children say things they have never heard, input doesn't include enough correction, grammar is too abstract for simple reinforcement

Cognitivism

- language develops from general cognitive development, not from language-specific module. Children must first understand concepts, then learn words to label them.

- Key assumptions: interaction with the environment, weak sense of nativism (children have some sort of cognitive abilities for language but not innate grammar)

- Language development depends on cognitive milestones

- Though comes first, language expresses existing though

- Schemas: mental representations of concepts. Children learn words by pairing them with pre-existing schemas.

**Invariant order of acquisition: children across languages reach stages in a similar order.

1. Birth to 18/24 months - sensorimotor intelligence period. Children understand world through sensation and activities. The world exists of the here and now.

2. Second year of life: object permanence - understands that objects exist independently and continue to exist when out of sight

Vygotsky Social Interactionism

- Language develops through social interaction

- Children learn best when guided by more knowledgable others. Adults provide hints, models, or prompts that help children acquire vocab, grammar, and conversational skills --> they internalize language and use it independently eventually/

- social contexts provide scaffolding and scaffolding gradually decreases as the child becomes more competent.

- Zone of proximal development: the gap between what a child can do independently (actual development level)  and what they can do with guidance(potential development). Recast: caregiver repeats child's utterance in the correct form, providing a subtle corrective signal.

Phonetics

The study of human speech sounds. How sounds are produced, transmitted and perceived. Concerned with the actual sounds humans can make

Phonology

the study of the sounds of a language and their combination - focuses on patterns, rules and meaning

Phone

A distinct speech sound in any language

Phoneme

a mental category of a speech sound that signals difference in meaning when modified/changed in a specific language

Orthography

regular spelling, often inconsistent and misleading

Phonetic Alphabet

One symbol = one sound, always consistent

Consonants

- Place, Manner, Voicing

Vowels

Tongue advancement, tongue height, lip rounding, tenseness

Coarticulation

the way in which the pronunciation of a speech sound is influence by the surrounding sounds in a spoken language

Assimilation

a sound becomes more similar to a neighboring sound - the modification of a sound in order to make it more similar to other sounds in the environment

- ex: labialization, palatalization

Dissimilation

the process where some sounds become more distinct and less like other sounds in the environment. Ex: library - one of the r sounds is frequently dropped

Phonological Development: Stage 1

- Reflexive Vocalization

- 0-2 Months

- Reflexive/Vegetative Sounds: fussing, crying, burping, swallowing - mainly for survival

- Quasi-Resonant Nuclei: vowel like sounds with consonantal elements, vibration of vocal folds, in response to interaction with a caregiver

Phonological Development: Stage 2

- Cooing and Laughter

- 2-4 Months

- primarily vowel sounds ~8 weeks

- turn-taking ~12 weeks

- laughter ~16 weeks

Phonological Development: Stage 3

- Vocal Play: extremes of loud and soft, high and low

- 4-6 months

- Non-speech grunts growls - adding consonants specifically stops, nasals and glides, some syllables

Phonological Development: Stage 4

- Canonical Babbling

- 6 months and older

- infants produce repetitive, rhythmic syllables containing a consonant and a vowel

- children share the same universal babbling patterns until the age of 10. After their first year, they start to tune into the sounds of their native language and their babbling becomes more similar to words in that language.

- they prefer frontal sounds /d/ /b/ and /m/ regardless of native language.

- show preference for certain sequence.

- first words start with their favorite babbling sequence

- Canonical syllables babbling is a predictive factor of earliest word onset

Canonical Babbling Syllable Structure

- CV: structure using their favorite babbling sequence (age 6-10)

- VC: by Aage 12-18; less common

- CVC: 12-18 months, but final consonants unstable

- CVCV: reduplication appears around 12-18 months (papa)

- CCV: 2-3 years but cluster reduction is common

Phonological Development: Stage 5

- Jargon stage

- 10 months and older

- long string of unintelligible sounds with adult-like prosody and intonation

- emergence of protowords (unique, consistent vocalizations infants use to represent specific objects, people, or actions before developing true words - invented sounds are not adult words but represent a crucial transitional milestone, showing that babies understand that sound combinations convey specific meaning)

How to measure phonological development

1. Normative Data - data from studies of large groups of children that captures common features of acquisition and helps us establish the basis of guidelines for typical phonological development

2. phonological inventories

- 3 elements for analysis of the inventory: a list of word-initial consonants, a list of word-final consonants, and vowels

- Accuracy of production: percent of consonants correct (PCC) = Number of correct consonants produced / total number of consonants

Formants

- vowels are distinguished by formants which are specific accoustic energy peaks (resonant frequencies) in the vocal tract that our ears identify as distinct speech sounds like "ah" "ee" or "oo.

- F1 = relates to jaw height (open/close)

- F2 = relates to tongue position (front/back)

Linguistic Features

- place, voicing, manner

- specific, analyzable components of language including sound, word structure, sentence construction, and meaning

- phonological, morphological, syntactic, lexical, pragmatic features

Prosodic Features

- fundamental frequency

- pitch (perceived fundamental frequency)

- intonation (alternation in fundamental frequency)

- stress (prosodic)

- duration

- junctures (length of sounds and pauses which helps chunk information into meaningful phrases)

Acoustic Features

- physical properties of sound waves = fundmental frequency, intensity (dB), duration, and spectral features

Different Talkers

- males = bigger vocal tract and lower pharynx

- F0 of female = 200 Hz

- F0 of male = 125 Hz

- prebuscent child also has higher F0 ~300 Hz

Infants' Hearing

- auditory system is fully developed by 3rd trimester

- newborns prefer to listen a passage they heard in the womb compared to one they didn't, speech rather than non speech, and their native language

Infants' Task in Deciphering Speech

- segmentation - segment single unit from continuous speech. Happens around 6 months, head turn preference procedure.

- discrimination - knowing that two sounds are different. Use it or lose it! Conditioned head turn paradigm --> perceptual tuning/narrowing - the older the infant the more difficulty they will have to discriminate between two sounds that are not phonemes in their language

- categorization - labeling a sound: categorical perception - a perception of distinct categories when there is gradual change in a variable along a continuum. Not specific to speech or humans and not absolute.

- comprehension - understanding the meaning

Infant directed speech

exaggerated prosody, higher-pitched voice, wider pitch range, longer pauses, shorter phrases, slower tempo.

What does lexical development entail?

1. words: basical vocabulary - recognizing and producing word forms. 2. Meaning: understanding what a word refers to and how it's used. Includes basic definition, any nuances (puppy vs. dog), or any multiple meanings (bark of dog vs bark of tree) 3. Grammatical category: knowing what kind of word it is and how it behaves in sentences. 4. Building a mental lexicon. **involves building a mental lexicon, mapping sound sequences to meaning and grammatical category

Perception vs Production

- perception of familiar words beings at about 6-7 months

- production or uttering the first word at about 10-12 months

Why is segmentation hard?

- coarticulation, auditory input is most of the time in the form of speech stream, variability in speakers (age, gender, health, mood, speech rate) leading to different styles.

The solution to segmentation

- words in isolation - very small percentage of the speech a child is exposed to, only about 9%, first word is often a word they have heard in isolation in mother's speech. Can be used as anchors! **by 4th birthday, children may hear 4 million words in isolation. First words usually are word they have heard in isolation in mother's speech.

- phonotactic constraints (language-specific rules governing allowed sound combinations, syllable structures (onsets/codas), and permitted positions of phonemes within words) - brain uses this statistically to recognize common patters

- distributional patterns: probabilities

- trochaic bias (stress pattern): phenomenon in language acquisition where young children show a preference for producing or perceiving strong-weak (𝑆𝑊) syllable patterns, known as trochees, over weak-strong (𝑊𝑆) patterns. Children often prioritize the stressed syllable, leading to early vocabulary.

Statistical Learning: Transitional Probability

TP (Y|X) = P (XY) / P(X)

- the likelihood of syllable Y occurring after syllable X

Lexical Development Milestones

~4 months: recognize own name

~6-8 months: first signs of word comprehension, responds to "no", familiar words, and own name in context.

~10-15 months: production of first word

~18 months: the spurt, a rapid vocab growth, also when two word combinations begin.

Mental Images and Referents

- Meaning is a mental representation (aka concept). When child learns a word they are not just memorizing sound. They are building a concept in their mind.

- abstract words: do not refer to physical objects but still have meaning (love, happy, tomorrow) - children must build understanding from experience not just visual images.

- mental images are idiosyncratic (personal or unique to individual) - everyones mental images can be different

- Referent: the actual thing the word represents. Ex: apple - referent: the actual apple you can hold and eat. The word is just the label.

How do we learn meaning? Intention Reading

- Children use social understanding to figure out meaning. Asks, "What is the speaker trying to refer to?"

- Relies on Theory of Mind: the understanding that others have thoughts, intentions, and goals.

- Evidence of ToM: eye gaze, pointing, and speaker attention (joint attention)

- By age 2: children use inner state words ("I'm sad.") shows understanding of internal states, which is when communication starts and becomes bidirectional. Not ego-centric and leads to empathy and language.

How do we learn meaning? Constraints

- cognitive biases or assumptions that children rely on to narrow down the potential meanings of new words, helping them to solve the "induction problem" - the challenge of figuring out what a new word refers to.

- Mutual Exclusivity: child assumes each object has only one label, leading them to reject a second name for a known object. Potential problem is that there can be more than one unknown object.

- Overextensions: child uses word too broadly (calling all four-legged animals dog)

- Underextensions: child uses a word too narrowly (calling only the family pet a dog and refusing to apply it to other dogs)

**over and under extensions make up 1/3 of 1-2 year old speech.

- Cross-situational learning: a language acquisition process where learners determine the meaning words by tracking their co-occurence with objects or actions across multiple, ambiguous situations. Advanced skill because it needs memory capacity.

- Whole object assumption: children assume a new word refers to an entire object rather than its parts, properties or substance

- Taxonomic principle: the tendency for "similar meanings to be expressed in similar forms". It involves organizing linguistic elements hierarchically or categorically based on shared attributes, such as grammatical, semantic, or structural characteristics

How do we learn meaning? Linguistic Cues

- syntactic bootstrapping: children use the syntactic structure (grammar) of sentences, specifically word order and the number of arguments, to infer the meaning of unknown words, especially verbs

- transitive and intransitive conditions

Inventing Words

How children create new words when they don't know the correct one yet? Follows 3 principles:

*Invention is not random; it follows systematic patterns

1. Simplicity: kids use simplest transformation possible by switched word types they already know. Deriving a verb from a known noun and vice versa. (Ex: I'm gonna hammer this" from the noun hammer) - children reuse familiar words and this shows they understand that words can shift roles depending on context.

2. Semantic Transparency: Creating a compound noun for an unknown sound. Kids invent new words whose meaning is easy to figure out from the parts. (Ex: "water-cup" for bottle) - word is logically constructer so even if it's not correct, you can understand it. This shows children are breaking meaning into its parts and recombining them in sensible ways.(e.g, plant-man for gardener)

3. Productivity: using grammatical cues found in adult speech to coin new words (e.g., adding -er to describe a doer of an action). Kids apply grammar rules they've learned to create new words. They are using patterns from adult language and extending them. And even when wrong, it shows they've learned the rule, not just memorized words.

Adult influence on semantic development: Prosody

- exaggerating intonation, longer pauses, sentence final position with marked street and pitch, producing words in isolation, better formalness and higher intelligibility

- facilities word acquisition (mapping)

- facilitates segmentation and word-boundaries recognition

Adult influence on semantic development: overheard speech

- requires joint attention for a successful learning

- ability starts at 18 months

- does not require one-to-one conversations, can pay attention to third party conversations

Individual differences in language acquisition

- contextual factors

- socio-economic status

- exposure to adults' input

- maternal language and literacy skills, and mental health

- child's unique personality and skills

- fathers' talk, vocab skills and book reading with children

Morpheme

smallest unit of meaning

Types of Function Words

- Auxiliaries - helping verbs like be, do, have, can (support a main verb to express tense, mood or voice). Accompany a main verb to denote tense, mood, or voice (She is running)

- Copula - linking verbs (be, seen, become). Connect a subject to a noun or adjective. (She is happy.)

- Determiners (aka articles) - a/an, the, that, those

- Prepositions - in, on, around, to

- Pronouns - she, her, herself

Words Learning Milestones

- 1-word (holophrastic): ~12 months, Single words used to convey full communicative intentions. 'Up' may mean 'pick me up.' 'No' may be used for refusal, rejection, or disapproval - 2-word, 18-24 months, wo words combined systematically, reflecting a consistent set of semantic relations (see table below). Children show knowledge of word order even at this stage - telegraphic, 2-3 years, Content words predominate; function morphemes and

function words largely omitted. Like a telegram: Baby

go there. No play that. What that - full syntax emerging, 3-5 years, Function morphemes acquired. Most basic sentence types (declarative, interrogative, negative, imperative) produced and understood. Passive and complex sentences still developing

Mean Length of Utterance

- count amount of morphemes used in utterance productively and then average them.

Agent

The participant that intentionally initiates or performs the action. In "John kicked the ball, "John is the agent. Intentionality is the key feature - agents act on purpose.

Action

the movement or verb

Object

receives action

Entity

labeled person/thing without action

Location

Place

Early Syntax

- Systematic: Words are combined following consistent rules from very early on. Children do not

randomly string words together.

• Hierarchical: Syntax is not just about linear order - sentences have nested phrase structure. 'The

girl squashed the ugly bug with the shoes' can mean the girl used the shoes to squash, or the bug

was wearing shoes. Structure, not just order, determines meaning - Order matters: 'The dog bit the man' and 'The man bit the dog' contain the same words but

different meanings. Even 2-year-olds respect word order in production and comprehension.

• Comprehension precedes production at the syntactic level, just as at the lexical level.

• Early syntax is predominantly content words: nouns dominate across languages, reflecting the

informativeness of naming in early communication.

• Function categories (determiners, auxiliaries, inflections) are largely absent in early child language

across languages

Roger Brown Stages

I. MLU = 1-2, one word, Single-word utterances; no grammatical morphemes. Content words only

II. MLU = 2-2.5, two word, Two-word combinations reflecting core semantic relations. Early grammatical morphemes begin to appear inconsistently.

III. MLU = 2.5-3, telegraphic (early), content words with minimal function words. More grammatical morphemes

present but not fully consistent

IV. MLU = 3-3.5, telegraphic (mid), Sentences become longer; most basic sentence types appear. Grammatical morphemes more consistently used

V. MLU = 3.5-4, telegraphic/adult. Approaching adult-like sentence structure. Most grammatical morphemes acquired. Complex sentences begin to emerge

Brown's stages

14 morphemes divided into early, middle, and late acquisition stages:

- Early: Present progressive (-ing), in, on, plural (-s).

- Middle: Irregular past tense, possessive (-'s), uncontractible copula (e.g., "This ismine"), articles (a, the), regular past tense (-ed).

- Late: Regular third-person singular (-s), irregular third-person, uncontractible auxiliary, contractible copula (e.g., "He's fast"), contractible auxiliary (e.g., "She's running").

The Wug Test

Linguistic experiment using invented words like "wug" to show how children learn language rules, not just memorize words. How children use inflectional morphology productively. "This is a wug. This is a picture of two ____."

Overregulation of Rules

- use -ed on irregular verbs (good)

~10% of the time

- over-irregularization; bring-brang, think- thunk happens < 0.2% of the time

- high frequency irregulars learned better than low frequency ones

**U-shaped development: The developmental curve has three phases: (1) correct use of the

irregular form (learned by rote as a vocabulary item), (2) incorrect overregularization after the

regular rule is acquired, (3) eventual correct and stable use of both the rule and the exceptions. The

child goes from 'went' to 'goed' and back to 'went

Why are function words omitted

- low semantic salience: dont carry much meaning

- Acoustic salience: Function morphemes are typically unstressed, short, and often reduced in

connected speech. They are harder to perceive than content words and therefore harder to extract

from the input

- another example of production lagging behind comprehension

Children's Early Comprehension of Syntax

- later half of second year, children start putting words together.

- Words are combined in a systematic way, reflecting Childs - knowledge of syntax

- Children's acquisition of syntax and grammar in general is not directly affected by child directed speech. This acquisition goes almost unnoticed

- Comprehension precedes production (which is also the case for semantics)

Studying Comprehension

Diary studies, act-out tasks using toys, direction tasks, picture choice task (syntactic judgment)

- Online comprehension tasks: preferential looking paradigm (using an eye tracker sometimes, or recording a video). This method looks at eye movement, and looking time. The child is seated on the caregiver's lap, she/he hears a sentence, and watches two videos simultaneously, one corresponding to the sentence. The amount of time the child spends looking at the correct video, and the eye movement is evidence of the child's comprehension/non-comprehension

Thematic Roles:

- Agent: The participant that intentionally initiates or performs the action. In "John kicked the ball, "John is the agent. Intentionality is the key feature - agents act on purpose.

- Patient: The participant that undergoes a change of state or is directly affected by the action. In "The vase was broken by the cat, "the vase is the patient because its state changes (from intact to broken).

- Theme: The participant that is moved, located, or whose state is described. In "Mary gave the book to John," the book is the theme — it's the thing being transferred. Theme and patient overlap in some frameworks, but theme typically emphasizes movement or location rather than being affected.

- Experiencer: The participant that undergoes a mental or sensory state rather than performing a physical action. In "Sarah loves chocolate," Sarah is the experiencer. No physical action happens; she's in a psychological state.

- Instrument: The object or means used to carry out the action. In "He cut the rope with a knife, "the knife is the instrument.

- Location: The place where the event or state occurs. In "The cat is sitting on the mat, "the mat is the location

- Recipient: The participant that receives something as a result of the action. In "John gave the book to Mary," Mary is the recipient.

Grammatical Roles

Subject

Verb

Object

Prepositional Phrase

Syntax

- Syntax emerges when children start producing two-word utterances.

- words are combined systematically and hierarchically - combinations are not random, children combine words in consistent patterns (e.g., agent + action like "Daddy eat").

- Hierarchically - sentences have internal structure where some words group together to form units. "eat cookie" is a verb + object structure. Even if the sentence gets longer later, the structure still organizes around relationships like subject → verb → object.

- children map semantic categories to grammatical categories (canonical) - children connect meaning to grammatical roles. (they use sentence structure (grammar) to help figure out who is doing what to whom—and even what a new word might mean.

Negation

- Negation in English depends on the type of verb, and usually requires an auxiliary verb.

1. With "be" verbs:

- We are hungry → We are not hungry (aren't)

- Rule: Add "not" after the verb → No extra auxiliary needed because "be" already functions as one

2. With main verbs (present tense)

- We like pizza → We do not like pizza (don't)

- Rule: Add do/does + not + base verb

3. With main verbs (past tense)

- We saw the movie → We did not see the movie (didn't)

- Rule: Use did not + base verb *Important: the main verb goes back to base form (see, not saw)

4 Stages of Negation Acquisition

1. Single word: "no", "don't", "no-more" - negation is just one word, not part of a full sentence yet

2. External Negation: "No go movies"; "No Mommy do it" - negation is placed outside the sentence (typically at the beginning)

3. Internal Negation W/O auxiliaries: "I no like it"; "I no want book"; "This not red" - negation moves inside the sentence but no auxiliaries yet. This is why is doesn't match adult grammar.

4. Internal Negation WITH auxiliary (more advanced): "Sarah can not have one"; "I am not sick". "I do not want milk." - Child now understand that negation needs an auxiliary. The structure is mostly correct

Auxiliaries Verbs

Auxiliaries are required for:

- Negation: "It goes there" → "It does not go there."

- Questions: "She caught it." → "What did she catch?"

Key Rule: the auxiliary carries tense, so:

"Did + catch" NOT "did + caught"

Once you use do/does/did, the main verb resets to base form

Stages of Question Development

1. Intonation Only: "You are coming?"

Same word order, just rising tone.

2. Adding Auxiliary (No Inversion Yet): "What they can eat?"

Auxiliary appears, but word order still incorrection (no inversion)

3. Subject - Auxiliary Inversion (Correct Form): "Where is he playing?"

Correct structure where auxiliary comes before subject

Declarative Sentence Syntax

~ 30 Months: Subject + Verb + Object → "She likes apples."

~ 2.5 - 3 years: Subject + Auxiliary + Verb + Object → "She can play the piano."

Child begins using auxiliary verbs and sentences become more grammatically complex.

~ 4 years: Subject + Verb + Indirect Object + Direct Object → "She put the box on the table"

- Adds location, indirect objects, or prepositional phrases. Sentences become longer and more detailed.

Sentence Types

- Declarative sentence - make a statement

- Interrogative sentence - ask questions

- Negative sentence - express something that is not true, not happening or not the case

- Imperative sentence - give a command

- Passive sentence - the subject of sentence is being acted upon

- Complex sentences - clauses embedded inside the main sentence (having more than one clause or verb)

- Coordinated sentences - multiple sentences joined together or NOUN

Later Syntax Development: Coordinations

- Joining two full ideas together - FANBOYS Ex: I want an apple and I want some milk.

- Start producing as early as 2.5 years

- "And": is the first and most common coordination word children use.

- Two types of coordination:

1. Phrasal Coordination (simpler): Joins words and phrases, not full sentences → "apples and bananas". This is easier and developes first.

2. Sentential Coordination (more complex): Joins two full sentences/clauses → "I want an apple and I want some milk". This is harder because it requires two full sentence structures. Needs more grammatical planning.

- Sentential NEVER used before phrasal → Children do not start with full sentence coordination. They first learn to join simple words/phrases

- Might develop simultaneously → Once development progresses, children may: Start using both types around the same time but phrasal is still earlier/easier

Later Syntax Development: Non-Standard Word Order

these are harder because they differ from basic SVO

1. Passive voice (e.g., The tacos were eaten → Object becomes the subject). Children are still mastering this in preschool and early elementary years.

- Active: The horse kicked the cow.

- Passive: The cow was kicked (by the horse).

- Rely on word order alone to determine the meaning.

- Fewer errors with irreversible verbs than reversible verbs

2. Clefts (e.g., It was the tacos that were eaten)

- Cleft sentences are used to emphasize one specific part of a sentence by splitting it into two parts. You take a normal sentence and highlight one element using this structure: 👉 "It is/was X that/who ..."

- Ex: Basic sentence: "She ate the tacos." Cleft sentence: "It was the tacos that she ate." Same meaning, but now you're emphasizing "the tacos"

- These sentences require extra structure, understanding of embedded and thats why children learn them later/

Later Syntax Development: Embedded Structures

- sentences inside other sentences - Relative Clauses

- Modifies a noun - Embedded sentence within a noun phrase that creates a more complex noun phrase. A relative clause adds extra information about a noun. Inside the relative clause, something is missing (a gap). That missing element = what "who/that" refers to.

1. Subject relative clause: subject - gap

- The boy [who____ is wearing a blue shirt] is my friend

- The subject is missing inside the clause - "who" replaces the subject. - If you remove "who," the clause is missing the doer of the action.

2. Object relative clause: object - gap

- The horse [that the boy rode ____ ] won the match.

- The object is missing inside the clause.

- The subject is still there ("the boy"). What's missing is what received the action

- Children have more difficulty with object-gap relative clauses than subject-gap relative clauses.

Common Errors When Learning Language

1. Errors of omission: "I walking" - The auxiliary word "am" is missing.

2. Errors of commission: you put something in, but it is in the wrong form. "I goed" should be "I went"

Comprehension of Syntax

• Word order comprehension: ~13 months. The Big Bird/Cookie Monster preferential looking study showed that 13-month-olds could use word order to determine who was doing what to whom.

• Complex syntax: Some structures are not fully mastered until age 9 or later. Chomsky's (1969) 'easy/hard to see' study: when shown a blindfolded doll and asked 'Is the doll easy or hard to see?' many children up to age 9 misinterpret the sentence, saying the doll is easy to see (confusing the surface subject with the logical object of 'see')

Big Questions in Syntax Acquisitio

The central puzzle of syntax acquisition is the Poverty of the Stimulus: children end up knowing more about grammar than their input can explain. This puzzle has two sides. The first is positive evidence.

Positive evidence only shows children what is allowed -it cannot show them what is not allowed. No

matter how many grammatical sentences a child hears, those sentences will never directly reveal which

sentences are ungrammatical, because ungrammatical sentences simply never appear in the input. They

are absent, not marked as wrong. The second side is negative evidence; corrections or signals that a

form is wrong. This could in principle fill the gap, but children rarely receive it consistently, and when

they do, they tend to ignore it. Both types of input therefore fall short, yet children still converge on the correct grammar - which is why the poverty of the stimulus is one of the strongest arguments for innate

linguistic knowledge

Poverty of Stimulus

The argument from the Poverty of the Stimulus (POS) holds that the input children receive is insufficient — both in quantity and type - to fully explain the grammatical knowledge they end up with.

Most powerful arguments for nativist theories of language.

• Limited input: Children hear only a subset of possible sentences in their language. Many

grammatical sentences are never uttered in their presence, yet children know they are grammatical.

• Ambiguous input: The sentences children do hear are compatible with multiple different

grammars. The input does not uniquely determine which grammar is correct. Yet children

converge on the target grammar.

• Rules not taught: No one explicitly teaches children that 'two my dogs' is ungrammatical, or why 'What can you do?' is grammatical while 'What you can do?' is not as a direct question. Yet children get these right