Language Acquisition I: Overview

1. Language Acquisition I: Overview Biological capacity to learn Stages of language acquisition Mar. 15

2. Learning language • One of the most impressive achievements of the human child is its ability to learn the complexities of a human language in just a few years, without any formal instruction. • Imagine you were a newborn infant: • How would you separate the sounds of speech from ambient acoustics? • when-we-speak-we-do-not-pause-between-words • Everyone’s speech is different: how to neutralize the differences? • How do we learn “dog” is a noun - and also a verb? • A sentence contains many parts - which ones “count”? (e.g., constituents) • Only humans--and all humans--but no other species have language. • Something must be in our genes. LING 001 Introduction to Linguistics, Fall 2010

3. Biological capacity • At birth, the infant vocal tract is in some ways more like that of an ape than that of an adult human. In particular, the tip of the velum reaches or overlaps with the tip of the epiglottis. • As the infant grows, she gradually stretched out the pharynx by lowering the larynx. The result of these changes is to make it possible for the tongue to move forward and back, up and down, in a way that creates resonant cavities of different sizes in various places in the vocal tract. LING 001 Introduction to Linguistics, Fall 2010

4. Biological capacity • At about seven months, "canonical babbling" appears: infants start to make extended sounds that are chopped up rhythmically by oral articulations into syllable-like sequences, such as [babababa], [nananana], [babigagu]. • No other animal does anything like babbling. It has often been hypothesized that vocal play and babbling have the function of "practicing" speech-like gestures, helping the infant to gain control of the motor systems involved in speech, and to learn the acoustical consequences of different gestures. LING 001 Introduction to Linguistics, Fall 2010

5. Biological capacity • Categorical perception • A change in some variable along a continuum is perceived, not as gradual but as instances of discrete categories • Discrimination between stimuli is much more accurate between categories than within them • The ability to discriminate is only as well as one can identify LING 001 Introduction to Linguistics, Fall 2010

6. Biological capacity • Categorical perception has been observed in many contrasting pairs of speech sounds. • Unique to language? No. Color perception is also categorical. • Unique to humans? Probably not. Chinchillas, quails, etc. can distinguish the bah-pah categories as well. LING 001 Introduction to Linguistics, Fall 2010

7. Biological capacity • Perceptual magnet effect • Phonetic categories have internal structure in which category prototypes, i.e., exceptionally good instances of phonetic categories, play an important role. • The prototype of a category functions like a perceptual magnet for other category members. The prototype attracts nearby members of the category, rendering them more perceptually similar to it than would be expected on the basis of physical distance alone. LING 001 Introduction to Linguistics, Fall 2010

8. Biological capacity • Perceptual magnet effect is unique to humans. LING 001 Introduction to Linguistics, Fall 2010

9. Biological capacity • Critical period: A child must be exposed to the input during a certain critical period, which roughly extends from birth until (the end of) puberty. Beyond puberty, then, it would no longer be possible to acquire a grammar in a normal way. • “Genie”, who was isolated from society until the age of 13 1/2, never learned to produce more than telegraphic speech. Mike paint.
 Neal not come sad.
 I like elephant eat peanut. • “Isabelle”, on the other hand, was isolated until the age of 6 1/2, and within a year and a half she had mastered complex grammar. Why does the paste come out if one upsets the jar?
 Do you go to Miss Mason's school at the university? Los Angeles Times, November 17, 1970 Girl 13, Prisoner Since Infancy, Deputies Charge; Parents Jailed LING 001 Introduction to Linguistics, Fall 2010

10. Biological capacity • “critical period” is easily observed in second-language acquisition. For example, a study of Chinese and Korean immigrants to the U.S. shows that the age of arrival to an English-speaking country is the main determiner of how effective the new language is learned. LING 001 Introduction to Linguistics, Fall 2010

11. Biological capacity • The critical period resembles other aspects of maturation in humans and animals. Failure to learn various other skills before a certain age makes it difficult or impossible to learn that skill later: • in ducklings: ability to identify and follow the mother • in kittens: ability to process visual images • in sparrows: ability to learn the father's songs • The course of language acquisition corresponds well to the general rate of metabolic activity in the brain, which peaks at the age of 4 and declines through adolescence. • It is difficult to say, however, to what extent this increased activity permits language learning, or is induced by it. LING 001 Introduction to Linguistics, Fall 2010

12. Stages of language acquisition • Language use by the child undergoes considerable elaboration between the age 2 and 5. • By age 5 or before, youngsters sound essentially adult. LING 001 Introduction to Linguistics, Fall 2010

13. Phonological development • Children from different linguistic communities exhibit significant similarities in their babbling. • Frequently found consonants: [p, b, m, t, d, n, k, g, s, h, w, j] • Infrequently found consonants: [f, v, θ, ð, ʃ, ʒ, tʃ, dʒ, l, r, ŋ] • Developmental order : • As a group, vowels are generally acquired before consonants; • Stops tend to be acquired before other consonants; • In terms of place of articulation, labials are often acquired first, followed by alveolars, velars, and alveopatals. Interdentals (such as [θ] and [ð]) are acquired last. • New phonemic contrasts manifest themselves first in word-initial position. Thus, the /p/-/b/ contrast, for instance, is manifested in pairs such as pat-bat before mop-mob. LING 001 Introduction to Linguistics, Fall 2010

14. Phonological development • Early phonetic processes: It's often useful to think of a child as applying a phonological rule to the adult form, in order to produce the child's output. • Simplification of syllable structure: delete coda consonants. [bi]"beat” [so]"soap” • Simplification of consonant clusters: Which consonant survives is a more complex matter, but often it will be a stop consonant. [koz] clothes [bʌp] bump • Deletion of unstressed syllables: Typically it's the stressed syllable that survives. Sometimes, one unstressed syllable can also be preserved. The result is generally a stressed plus an unstressed syllable (a trochaic foot). [ba] bottle [dedo] potato LING 001 Introduction to Linguistics, Fall 2010

15. Production vs. perception • Children’s ability to perceive the phonemic contrasts of their language develops well in advance of their ability to produce them. Adult: This is your fis? Child: No, my fis. (Rejects repeated imitations.) Adult: Oh, that is your fish. Child: Yes, my fis. • Another possibility is that the child was making a very subtle distinction that was not perceived by the adult. LING 001 Introduction to Linguistics, Fall 2010

16. From more to less • Experience with language alters speech perception ability, we become attuned to the phonemes of our own languages and insensitive to others • Japanese infants can distinguish [r] vs. [l] (but their parents can’t). • You could distinguish these sounds before… Retroflex stop vs. dental stop in Hindi LING 001 Introduction to Linguistics, Fall 2010

17. Vocabulary development • By age fifteen months or so, the average child has a vocabulary of fifty words or more. • Entities: daddy, apple, dog, shoes, ball, car, book, etc. (the most) • Properties: hot, more, etc. • Actions: see, eat, etc. • Personal-social: hi, bye, etc. • A “typical” profile for vocabulary development: • 18 months: 50 words • From 18 months to 6 years: 10 words per day • 6 years: 14,000 words • From 6 years to 17 years: up to 20 words per day • 17 years: 60,000 words LING 001 Introduction to Linguistics, Fall 2010

18. Morphological development • Because English has many examples of irregular inflection, children sometimes begin by simply memorizing inflected words on a case-by-case basis. • When they subsequently observe the generality of -s as a plural marker and -ed as a past tense marker, they sometimes use these suffixes for the irregular forms - overgeneralizations or overregularizations. LING 001 Introduction to Linguistics, Fall 2010

19. Semantic development • Under and over-extensions:Young children often use words in ways that are too narrow or too broad. • bottle used only for plastic bottles; • teddy used only for a particular bear; • dog used for lambs, cats, and cows as well as dogs; • kick used for pushing and for wing-flapping as well as for kicking. • Q: Is every ball on a box? A (preschooler): No, one of the boxes doesn’t have a ball on it. LING 001 Introduction to Linguistics, Fall 2010

20. Syntactical development • During the second year, word combinations begin to appear. • Novel combinations appear sporadically as early as 14 months. • At 18 months, 11% of parents say that their child is often combining words, and 46% say that (s)he is sometimes combining words. • By 25 months, almost all children are sometimes combining words, but about 20% are still not doing so "often.” • A notable feature of children’s two-word utterance is that they almost always exhibit the appropriate word order. All wet See baby Dry pants I sit LING 001 Introduction to Linguistics, Fall 2010

21. Syntactical development • In the early multi-word stage (also called the telegraphic stage), most grammatical/functional morphemes are missing. Chair broken. Daddy like book. What her name? Man ride bus today. Car make noise. I good boy. • In the telegraphic stage, quite elaborate types of phrase structure emerge: a head and a complement (like book, ride bus), a modifier (good) full-fledged sentences LING 001 Introduction to Linguistics, Fall 2010

22. Universal grammar • Systematic errors in child language that cannot be attributed to the language it is learning can be attributed to possible human grammars (found elsewhere in the world/time) A my pencil (Greek) Tickles me (Chinese) I don’t want no milk (Spanish) Who do you think who is in the box (German) • These grammars are not available in the environment but come from inside: Universal Grammar, the totality of possible human language structures. • Some errors never happen - not allowed by the universal grammar. “Ask Jabba if the dog that is sitting on the bench is happy?” • Is the dog that __ sitting on the bench is happy? (not a single kid did this) • Is the dog that is sitting on the bench __ happy? LING 001 Introduction to Linguistics, Fall 2010

23. Language is innate • There is a set of universal principles, like the principle of structure dependence, that all languages obey. • The differences among languages can be described by about a few dozen of parameters. • Learning a language is to fix the values of the parameters - by unlearning all other possible languages. • Evidence from the study of the brain and the study of diseases and other afflictions supports the conclusion that language is innate. • Specialization of brain areas for language • Systematic correlation between impairment of certain linguistic abilities and specific areas of brain injury • These findings will be reviewed later in the semester LING 001 Introduction to Linguistics, Fall 2010