First language acquisition

1
First language acquisition

• How do children learn language?

2
Some observations

• Virtually all children learn to speak or sign
  their native language.
• True across cultures, economic situations,
  educational backgrounds.
• Childrens language development follows the same
  time course for children acquiring all languages.
• Similar to other biological endowments like
  vision and the ability to walk
• The answer to How do children learn language?
  must hold for all children, all languages and all
  societies.

3
What input do children need to learn a language ?

• Interaction with language
• Not mere exposure hearing children of deaf
  parents do not learn spoken language from TV
• Primary input may be from other children
  societies differ in the extent to which adults
  talk to children

4
Do parents teach children how to speak?

• Reinforcement Theory Parents teach children
  language by correcting errors and rewarding their
  grammatical utterances
• Many parents correct their young childrens
  errors, but many do not.
• Parents usually correct content, not grammar.
• Kid Matt goed to school .
• Mom No, Matt went to the PARTY.
• Correcting a young childs grammar is an exercise
  in futility.

5
A famous example

• Kid Nobody does like me.
• Mom No, say, nobody likes me.
• Kid Nobody doesnt like me.
• eight repetitions of this dialogue
• Mom No, listen carefully say Nobody likes me.
  
• Kid Oh, nobody dont like me.
• (from McNeill, 1966, p. 69, as cited in Berko
  Gleason Ratner 1993)

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Positive evidence vs. Negative evidence

• The evidence that children use to find patterns
  in their language is positive evidence (examples
  of possible sentences), not negative evidence
  (explicit correction).

7
Do children learn to talk by imitating what they
hear?

• Imitation Theory Children learn language by
  mimicking what they hear.
• Children do not talk like miniature adults.
• They produce forms and constructions that have no
  adult model.
• No bed, nana (banana), Mommy tie shoe
• Direct imitation, i.e., repeating a parents
  sentence or phrase word-for-word is rare in child
  speech

8
Another Theory of Language Acquisition

• Active Construction of a Grammar Theory
• Children build on innate abilities.
• They discover patterns in the language around
  them and hypothesize rules that account for these
  patterns.
• Childrens productions obey these rules, although
  they may violate rules of the adult grammar.

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How do people talk to babies and young children?

• Child-directed speech, Motherese
• different lexicon (baby words)
• topics Here and now
• conversation play, turn taking
• high pitch, exaggerated intonation
• Does it help?
• Holds infants attention
• Some evidence that it helps infants learn
• Cannot be an absolute requirement
• Some families and cultures do not adapt speech in
  this way

10
Conversation play

• Mom Hello. Give me a smile. gentle poke
• Baby yawns
• Mom Sleepy, are you? You woke up early today.
• Baby opens fist and gurgles
• Mom Do you want to hold Mommys hand?
• Baby grasps mothers finger
• Mom Yeah, thats what you wanted.

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Preferential Looking Paradigm
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Perceptual abilities of infants

• Newborns prefer their mothers voice
• Newborns prefer listening to their native
  language
• Infants less than a year old can distinguish
  between sounds that are not phonemic in their
  native language
• Babies as young as 4 mo. know that certain mouth
  shapes produce certain vowels
• 7 ½ mo. olds prefer stories with familiar words
• 9 mo. olds prefer listening to non-words that
  conform to patterns in their native language

13
An infants earliest sounds

• earliest sounds burping, sighing, sucking,
  crying
• 2 mos. Cooing
• 4 mos. consonant-like sounds, more variation,
  sustained laughter
• 6 mos. babbling (ba, da, ga)
• 8 mos. reduplicated babbling (ba ba ba ba, da
  da da)
• 10 mos. varied (jargon) babbling (ba di bi, da
  gu ba)
• Babbling reflects the phonology of the infants
  native language (e.g., Japanese babies produce
  more ks)

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Babbling in infants acquiring a signed language

• Deaf infants babble vocally, but stop much
  earlier than hearing infants
• Deaf and hearing infants acquiring a signed
  language babble manually
• Manual babbling distinguishable from gestures
  (Petitto Marentette (1991))
• handshapes found in ASL
• syllable types found in ASL
• location restricted, as in ASL

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Earliest Words and the One-Word Stage

• starts around 11, 12 months
• Babbling continues
• 1st words refer to things that are very salient
  to child
• people, objects, pets
• May only loosely resemble adult model
• Not always easy to identify
• Ba!
• Holophrastic carry meaning of whole sentence
• Milk!
• Comprehension outpaces production
• Comprehension vocabulary much smaller than
  production vocabulary
• Children in one-word stage can understand longer
  utterances

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Two-Word Stage

• Starts 18-24 mos.
• Vocabulary of more than 50 words
• Utterances have consistent word order
• Express certain semantic relations
• Agent action baby sleep
• Action object kick ball
• Entity location teddy bed
• Possessor possessive Mommy book
• Telegraphic no function words or function
  morphemes (on, -s, etc.)

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Word learning strategies

• Starting late in the two-word stage, children
  learn many new words a day
• They have strategies to help with the task.
• Whole object principle
• A word refers to the whole object, not just a
  part.
• One name principle
• Each object has one name. A new word will not
  mean the same thing as an existing word.

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Overextensions and underextensions

• Overextension child uses a word to refer to a
  large set than adults do
• doggy dogs, cats, stuffed animals, feather
  dusters
• Underextension child uses a word in a more
  restricted sense than adults do
• doggy only beagles or German shepherds

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Beyond the two-word stage

• No three-word stage after two-word stage,
  children produce utterances of different lengths
  (1, 2, 3, 4, 5 words)
• Still telegraphic, function words and function
  morphemes appear
• Typically acquired in a consistent order
• -ing She walking
• -s She walks
• -ed She walked

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Plurals

• Two kinds of English plurals
• regular shoe/shoes, dog, dogs
• irregular man/men, sheep/sheep
• Child often uses adult irregular form (say, men)
  for a while, then start using the regular form
  (mans).
• error reflects refinement of grammar
• Child has learned the rule that plural is formed
  by adding s
• overgeneralizes

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A classic test
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• By 3 years, vocabulary of 1000 words
• 80 of utterances understandable even by
  strangers
• Do not yet have adult command of all sentence
  structures.
• Must still learn many metalinguistic skills