Language Acquisition

Language Acquisition: The Problem

• Since language is productive, children must acquire not just words but a generalized grammar with all its components and rules.

• This is a lot--How do children learn all these rules?

• Rules, unlike words, are never explicitly stated, so the child cannot just memorize them: they must somehow figure the rules out on their own.

• Various theories have arisen that attempt to account for how children acquire language. We will now discuss the currently still most discussed ones

Innateness Hypothesis

• Many theories of language acquisition assert that language ability is innate in humans. That is, humans are genetically predisposed to acquire and use language (though not any particular language, of course). This theory claims that babies are born with the knowledge that languages have patterns and with the ability to seek out and identify those patterns.

• Some theories propose that humans have innate knowledge of some core characteristics common to all languages, such as the concepts of ‘noun’ and ‘verb.’ These basic features shared by all languages are called linguistic universals, and the theoretically inborn set of structural characteristics shared by all languages is known as universal grammar.

• We don't know what the contents of the universal grammar might be, so this is currently an active area of research in linguistics

• Innate behaviors are present in all typical individuals of a species, whereas learned behaviors are not.

• Walking, for instance, is a behavior for which humans are genetically predisposed (that is, humans learn to walk as a natural part of development, without being explicitly taught), but playing the piano or riding a bicycle must be specifically taught. Is talking like walking, or is it like playing the piano?

• If language acquisition has each of these characteristics of biologically controlled behaviors, we can safely assume that it is a genetically triggered behavior

Lenneberg’s characteristics of biologically controlled behaviors:

• 1. The behavior emerges before it is necessary.

  • Each individual needs the ability to use language in order to take care of other basic needs. But children ordinarily begin to speak a language between the ages of twelve and twenty-four months, long before their parents have stopped providing them with the necessities of life.

• So language is a behavior that, like walking, emerges well before children have to fend for themselves

• 2. Its appearance is not the result of a conscious decision.

• 3. Its emergence is not triggered by external events (though the surrounding environment must be sufficiently “rich” for it to develop adequately).

  • Language is neither the result of a conscious decision nor triggered by external events.

• Compare: Children decide whether or not they want to learn to play baseball or checkers, but they do not make a conscious choice about acquiring a native language; it’s just something that all children do.

• Compare: If you grew up hearing brilliantly played piano music, you wouldn't automatically pick up that skill the way we seem to pick up language

• 4. Direct teaching and intensive practice have relatively little effect

  • While it is true that a child has to be exposed to language, a child’s caretakers

  • don't need to make a special effort to teach the child to speak.

  • But doesn’t intensive teaching help children learn language?

  • Surprisingly, it does not seem to have much of an effect. Children don’t necessarily perceive (or correct!) their mistakes just because an adult points them out.

    • Child: Nobody don’t like me.

    • Mother: No, say “nobody likes me.”

    • Child: Nobody don’t like me. (repeated 8 times)

    • Mother (now exasperated): Now listen carefully! Say, “Nobody likes me.”

    • Child: Oh! Nobody don’t likes me

• 5. There is a regular sequence of “milestones ” as the behavior develops, and these can usually be correlated with age and other aspects of development.

• Children master linguistic skills in a certain order. Although there is some variability in the milestones and the ages at which children achieve them, there is a path of developmental stepping stones that all children follow.

• Example

  • 12-18 months: Can produce only one word at a time.

  • 18-24 months: Begin to use two-word utterances with a single intonational pattern

• 2 years: Begin to use pronouns, though some are often still confused

• 6. There is likely to be a “critical period” for the acquisition of the behavior

  • Evidence from neglected children, feral children (who grew up in the wild), second-language acquisition, and an emerging sign language in Nicaragua suggests that there appears to be a critical period, at least for some aspects of language acquisition

• Despite our lack of a complete understanding of the acquisition process, we can conclude that language acquisition shows characteristics of at least to some degree being an innate human behavior

Active Construction of a Grammar Theory

• The most influential theory of language acquisition

• Idea: Children invent the rules of grammar themselves

• Assumption: Ability to develop rules is innate, but the actual rules are based on the speech children hear around them

• Process: Children listen to the language around them and analyze it to determine the patterns that exist. When they think they have discovered a pattern, they hypothesize a rule to account for it. They add this rule to their growing grammar and use it in constructing utterances

• Example about a child learning past tense

• First hypothesis: add the suffix -ed to all verbs

  • All past tense verbs will be constructed with this rule, producing forms such as holded and eated alongside needed and walked

• When children discover that there are forms in the language that do not match those produced by this rule, they modify the rule or add another one to produce the additional forms.

• Eventually, the child has created and edited their own grammar to the point where it matches an adult’s grammar

Connectionist Theories

• Assumption: Children learn language by creating neural connections in the brain

• Process: A child develops connections through exposure to language and by using language. Through these connections, the child learns associations between words, meanings, sound sequences, and so on.

• Example: A child may hear the word bottle in different circumstances and establish neural connections every time the word is heard. Such connections can be to the word itself, to the initial sound /b/, to the word milk, to what the bottle looks like, to the activity of drinking, and so on.

• Thus, instead of developing abstract rules, according to connectionist theories, children exploit statistical information from linguistic input. Such theories assume that the input children receive is indeed rich enough to learn language without an innate mechanism to invent linguistic rules. (→ psssst 🤫 LLMs!)

• Evidence: When asked to complete the phrase “This man is fringing (nonsense word); Yesterday, he _____,” many children create nonsense irregular forms such as frang or frought instead of the nonsense regular form fringed. 

• → Problem for the Active Construction of a Grammar Theory: If children invent rules and then learn exceptions to the rules, they should produce fringed as the past tense of fring because it is not one of the learned exceptions.

• → Connectionist Theory: Children are expected to sometimes produce irregular forms because of their exposure to words like sing, ring, or bring

• The solution doesn't need to be either / or. It is possible that children both develop rules and also make use of statistical data, e.g., that acquisition of grammatical rules proceeds according to a hybrid model and that children actively construct a grammar by establishing and exploiting neural connections

Social Interaction Theory

• Idea: Children acquire language through social interaction, with older children and adults in particular.

• Process: Children and their language environment are seen as a dynamic system: children need their language environment to improve their social and linguistic communication skills, and the appropriate language environment exists because it is cued by the child (i.e., children prompt their parents to supply them with the appropriate language experience they need).

• Similar to Active Construction of Grammar Theory, social interactionists believe that children must develop rules and that they have a predisposition to learn language.

• But social interaction theorists emphasize social interaction and the kind of input that children receive, instead of assuming that simply being exposed to language use will suffice

• Prediction: The ways in which older children and adults talk to infants play a crucial role in how a child acquires language.

• In many Western societies, speech to infants (child-directed speech) is slow and high-pitched and contains many repetitions, simplified syntax, exaggerated intonation, and a simple and concrete vocabulary. Compare:

• A. See the birdie? Look at the birdie! What a pretty birdie!

• B. Has it come to your attention that one of our better-looking feathered friends is perched upon the windowsill?

• In addition to saying A rather than B, they are likely to point at the bird to share the observation. Social interactionists believe that the way adults speak to children and interact with children is crucial to acquiring language

The Phenomenon of Overgeneralization

• The evolution of the plural marker

  • 1. At first, no plural marker is used: Nouns appear only in their singular forms (e.g., man).

• 2. Irregular plural forms may appear, i.e., a child may say men instead of man

• 3. The child discovers the morpheme -s and suddenly applies it uniformly to all nouns. In some cases this involves overgeneralization of the rule of plural formation; for example, the plural of man becomes mans. During this stage the child often leaves nouns ending in sibilants (e.g., nose, house, church, etc.) in their singular forms.

• 4. Once children discover the generalization about how the plurals of these nouns are formed, they may go through a brief period during which [-əz] is added to all nouns, giving not only houses but also man-es or even mans-es.

• 5. The child produces all plurals correctly, except for the irregular ones they haven’t encountered yet (such as oxen or sheep, or cacti). These are learned gradually and may not be fully acquired by the time the child is five years old

Wug Test

• Three variants of English plural -/s/ ending:

  • /s/: cats, cuffs, laps, …

  • /ɪz/: kisses, dishes, judges, …

  • /z/: girls, chairs, boys, …

Child-Directed Speech

• Speech directed at children is called infant-directed speech or child-directed speech.

• How adults talk to children is influenced by three things.

  • 1. Adults have to make sure that children realize that they are being addressed.

    • Tools: Use name, speak in a special tone of voice, touch the child

  • 2. Choose concepts that maximize the child’s chances of understanding what is being said. For example, talk about what the child is doing, looking at, or playing with at that moment.

• 3. Choose a particular style of speaking that they think will be most beneficial to the child. Tools: Talk quickly / slowly, use short / long sentences, etc.

• → Children are presented with a specially tailored model of language use, adjusted to fit, as far as possible, what they appear to understand

• Adults also teach explicit turn-taking!

  • Ann: [smiles]

  • Mom: Oh, what a nice little smile! Yes, isn’t that nice? There. There’s a nice little smile.

  • Ann: [burps]

  • Mom: What a nice wind as well! Yes, that’s better, isn’t it? Yes.

  • Ann: [vocalizes]

  • Mom: Yes! There’s a nice noise.

• Whatever the infant does is treated as a conversational turn, even though at this stage the adult carries the entire conversation alone.

• As infants develop, adults become more demanding about what “counts” as a turn. Yawning or stretching may be enough at three months, but by eight months, babbling is what really counts. And by the age of one year or so, only words will do

Bilingualism

• The majority of people in the world are bilingual (speakers of two languages) or multilingual (speakers of more than two languages).

• Definition (here): Being able to hold a conversation with monolingual speakers of two different languages.

• Major ways to become bilingual:

  • Simultaneous bilingualism (learning more than one language from birth)

  • Sequential bilingualism (begin learning their second language as young children)

  • Second-language acquisition (learning second language later in life)

Bilingual First-Language Acquisition

• Typical feature of bilingual children’s speech: language mixing or code-switching

  • Definition: Using more than one language in a conversation or even within a phrase.

• Example: Mario, a boy who grew up mostly in the United States and whose parents spoke Spanish to him, frequently used both English and Spanish in the same sentence, as in the following examples (Fantini 1985):

  • Sabes mi school bus no tiene un stop sign.

  • “You know, my school bus does not have a stop sign.”

  • Hoy, yo era line leader en mi escuela.

  • “Today, I was line leader at school.”

• Recent research has shown that bilingual children can differentiate their languages by the time they are four months old, i.e., long before they utter their first words.

• If bilingual children can differentiate their languages well before they utter their first word, why do they mix languages?

• → Mario does not just randomly mix English and Spanish. Instead, he seems to use some English nouns in what are basically Spanish sentences. Furthermore, all of the English nouns he uses are related either to his school experience in the United States (school bus, line leader, etc.) or to typically American items (cranberries, marshmallows, etc.)

• Bilingual vs. monolingual children

  • Research suggests that bilingual children may lag behind in vocabulary of one of their two languages (note that they have to learn twice as much), but they have usually caught up by the time they reach puberty.

    • This doesn’t mean that they can’t communicate their ideas; but have a preferred language for certain concepts.

    • On the other hand, growing up bilingually may have some cognitive advantages, such as advanced meta linguistic understanding of arbitrariness.

    • Other than that, bilingual children go through the same stages of language acquisition as monolingual children of each of the languages

Second-Language Acquisition

• People learning a language later in life usually attain different levels of competence

• Some people achieve native-like competence in a second language, but the vast majority of second-language learners do not.

• Speakers may learn the syntax and vocabulary of a second language perfectly (although even this is rare), but few learn the phonological system that well.

• Thus, most second-language speakers speak with a foreign accent

• A learner's native language contributes to second-language acquisition

  • A Dutch speaker will have an easier time learning English than, for example, a Chinese speaker, because Dutch and English are closely related languages with similar grammatical and phonological systems. This is called transfer. Transfer can be positive or negative, depending on whether it facilitates or inhibits the learning of the second language.

• The native language can also inhibit learning the second language. E.g., our specialization for the sounds of our native language can interfere with learning the phonological system of a second language and is one of the reasons why second-language learners usually have a foreign accent.

• Example: [p] and [ph] in English vs. Hindi (Lecture 3)