Language Acquisition and Development: Lexicon, Syntax, Morphology, and Pragmatics

Vocabulary practice flashcards covering lexical development, syntactic milestones, sentence comprehension strategies, morphology, and communicative development.

Word

An arbitrary sound sequence that symbolizes meaning, possesses reference, and can stand alone.

Context-Bound Words

Early child words restricted to one particular context or specific referent (e.g., saying "car" only when viewing cars from a specific window).

Context-Flexible Nominals

Early noun-like labels (such as "ball", "shoe", or "baby") that a child can apply flexibly across multiple situations and exemplars.

Context-Flexible Non-Nominals

Early words across non-noun categories—including verbs, modifiers, personal, social, and function words (such as "give", "dirty", "more", and "no")—used across varied contexts.

Underextension

A lexical error where the meaning of a word is applied too narrowly, such as limiting the word "doggie" strictly to the family pet.

Overextension

A lexical error where a word's meaning is stretched too broadly, such as using "doggie" to refer to horses, cows, and pigs.

Natural Partitions Hypothesis

The hypothesis proposing that nouns dominate early vocabularies because physical objects are perceptually obvious, whereas verbs require observing relational interactions while in use.

Relational Relativity Hypothesis

The hypothesis positing that verb meanings are more difficult to acquire because they vary cross-linguistically (e.g., English verbs encode manner of motion, whereas Spanish verbs encode direction of motion).

Word Spurt

A non-linear surge in vocabulary acquisition occurring around the $50^{\text{th}}$ word (approximately $18$ months), where learning accelerates from $8\text{--}11$ words per month to $22\text{--}37$ words per month.

Naming Insight

The developmental realization occurring around $18$ months that words name objects and that all objects have names.

Fast Mapping

The capacity to form an initial hypothesis about the referent of a novel word after very few exposures (or a single exposure at $13$ months).

Whole-Object Assumption

A lexical constraint leading children to assume that a novel label refers to an entire object rather than its parts, properties, or substance.

Taxonomic Assumption

A lexical constraint guiding children to extend a newly learned word to items of the same taxonomic kind rather than to thematically associated objects.

Syntactic Bootstrapping

The strategy of using the grammatical structure of a sentence to deduce the meaning of an unfamiliar word.

Coalition Model of Language Comprehension

Hirsh-Pasek and Golinkoff’s framework proposing that children recruit multiple perceptual, social, and linguistic cues to learn word meanings, with different cues weighted differently across development.

Order of Sentence Form Acquisition

The developmental sequence of sentence forms acquired by young children, progressing from imperatives, to declaratives, and finally to interrogatives.

External Negative Marker Stage

The earliest phase of syntactic negation where a negative element is placed outside the clause boundary (e.g., "No . . . Wipe finger" or "Wear mitten no").

Internal Negative Marker Stage

The intermediate negation stage where negative markers are placed inside the sentence but lack copulas or auxiliary verbs (e.g., "I no want that" or "I not gonna cry").

Probable Event Strategy

A sentence comprehension heuristic where a young child relies on real-world knowledge to perform the action normally associated with an object, rather than parsing the syntax (e.g., brushing hair when asked to "kiss the brush").

Child-as-Agent Strategy

A sentence comprehension heuristic where the child acts on named objects by assuming that they themselves are the agent of the mentioned action.

Verb Island Hypothesis

A usage-based proposal stating that $2$-year-old children do not possess an abstract category of verbs, but instead build individual, item-based grammatical frames around each specific verb.

Dual Process Model

A linguistic account holding that regular verb past tenses are generated via an abstract mental rule (affixing $-ed$), whereas irregular past tenses are retrieved from associative memory.

Tadpole-Frog Problem

The theoretical debate over continuity versus discontinuity in language acquisition, asking how a child's early semantically based grammar transforms into the abstract syntactic grammar of adulthood.

Open-Class Words

Content words—including nouns, verbs, and adjectives—that carry lexical meaning and freely admit newly coined vocabulary items.

Closed-Class Words

Function words—such as auxiliaries, prepositions, and determiners—that serve grammatical roles and belong to static categories that resist new additions.

Inflectional Bound Morphemes

Affixes added to words to mark grammatical features (such as tense or number in "walk-ed" or "card-s") without altering the word's syntactic category.

Derivational Bound Morphemes

Affixes (such as "-ment" in "establishment" or "-ly" in "carelessly") that modify meaning and may shift the syntactic category of the root word.

Vertical Constructions

Transitional forms at the single-word stage ($12\text{--}18$ months) in which two separate single-word utterances are linked in sequence to convey a unified meaning (e.g., "Ow. eye").

Unanalyzed Wholes

Multi-word sequences stored and retrieved as single lexical units without an understanding of their constituent grammatical elements (e.g., "Idon'tknow?" or "Allgone").

Telegraphic Speech

Early multi-word utterances ($24+$ months) composed largely of open-class content words with the omission of closed-class function words and bound morphemes.

Mean Length of Utterance (MLU)

A quantitative index of grammatical growth computed as: $\text{MLU} = \frac{\text{Total Morphemes}}{\text{Total Utterances}}$.

Wexler’s Optional Infinitive Account

The theory proposing that children omit bound tense affixes because they undergo a maturational stage in which finite verbs are not obligatorily marked for tense and agreement.

Linguistic Competence

The underlying knowledge that enables a speaker to produce and comprehend grammatically correct and meaningful sentences.

Communicative Competence

The ability to produce and interpret sentences appropriately within varying social and contextual interactions.

Locution

The formal linguistic structure and literal grammatical utterance of a speech act (e.g., declarative, question, imperative).

Illocutionary Force

The intended communicative goal or function of a speech act (such as requesting, promising, threatening, or warning).

Perlocution

The consequential effect or external outcome that a speech act produces in the listener (e.g., directing an action or gaining attention).

Grice’s Conversational Maxims

Four cooperative discourse principles: Quality (be truthful), Quantity (provide the right amount of information), Relation (be relevant), and Manner (be clear and unambiguous).

Perlocutionary Phase

The communicative stage (birth to $10$ months) during which an infant's vocalizations and actions affect caregivers without intentional communicative purpose.

Illocutionary Phase

The communicative stage ($10\text{--}12$ months) where infants exhibit clear communicative intent using pre-linguistic vocalizations and gestures, but lack adult linguistic forms.

Locutionary Phase

The communicative stage beginning at approximately $12$ months wherein a child expresses communicative intentions using conventional, adult-like linguistic forms.

Proto-imperatives

Preverbal communicative signals used by infants during the illocutionary stage to solicit objects or request adult actions.

Proto-declaratives

Preverbal communicative acts used by infants to direct adult attention to an external object or event purely to share focus and experience.

Secondary Intersubjectivity

The developmental capacity emerging around $10$ months to simultaneously coordinate social attention between an external object and another person to share experiences.

Proto-conversations

Early interactional, turn-taking sequences and non-verbal routines between caregiver and infant that precede formal verbal dialogue.

Theory of Mind

The cognitive insight that other individuals hold independent internal mental states—such as beliefs, desires, and intentions—that may differ from one's own.

Private Speech (Piaget)

Egocentric, non-communicative solitary talk used by children to explore and practice language as a reflection of cognitive egocentrism.

Private Speech (Vygotsky)

Self-directed speech originating from social interaction that functions as an explicit cognitive tool for behavioral self-guidance before turning inward.

Registers

Sociolinguistic speech adjustments where speakers modify their language style and vocabulary to match different audiences and social settings.