Grammaticality Judgments

• Do you want to come with? 20%• I might could do that. 38%• The pavements are all wet. 60%• Y’all come back now. 38%• What if I were Romeo in black jeans? 61%• Colorless green ideas sleep furiously. 61%• John gave Mary the book 97%• John donated Mary the book 30%

Summary to this point

• Children appear to be learning an abstract set of grammatical rules and not simply memorizing what they hear.– Use language productively

– Overregularization of rules

• How do they do it?– Biological predisposition to learn language

– What’s the role of input?

– “Motherese” & Negative Evidence

The Learnability Problem

• Gold’s (1967) Theorem: Mathematical proof that showed that many classes of language, including natural human language, cannot be learned solely through positive evidence, i.e. which sentences are grammatical.

• Multiple possible grammars would be consistent with such evidence. How to choose which one is your grammar?

• Need negative evidence: which sentences are ungrammatical?

The role of input: Motherese

• Characteristics of Motherese– Simple clauses (i.e. few embedded clauses) – Grammatical (few hesitations, etc) – Short sentences – Redundant (lots of repetition) – Limited vocabulary – Here and now – Higher pitch and special intonation (especially

when talking to babies). – Slower than adult to adult speech

The Role of Input: Motherese

• Does Motherese help kids learn language? • Well, not much evidence that it does• First, Motherese is NOT universal (Ochs &

Schiefflien (1982)• Newport et al (1977), Furrow et al. (1980) found

very few relations between motherese and language development– More mother questions more child auxilliaries– More mother verbs fewer child verbs

The Role of Input: Negative Evidence

• Brown & Hanlon (1970), Hirsh-Pasek et al. (1984) and others: parents do not frequently, reliably, or directly provide negative evidence to their children about their ungrammatical utterances

• They tend to correct semantic errors, not syntactic errors

• Maybe parents are providing more subtle feedback about their children’s speech?

Negative Evidence

• Maybe there’s some other way that parents and other adults provide feedback to kids.

• Bohannon & Stanowicz (1988): Parents respond differently (in terms of probability) to grammatical vs. ungrammatical child utterances:– Grammatical utterances more likely to be followed by

exact imitation. (11% vs. 3%)– Ungrammatical utterances more likely to be followed

by a recast, e.g. following “The doggie eated the foods.” with “Yes, the doggie ate the food.” (5% vs. 15%)

Could this Kind of Feedback Work?

• Gordon (1990):– In Bohannon & Stanowicz’ data only 34% of ungrammatical

utterances were followed by negative evidence (e.g. recasts) and 30% of negative evidence followed grammatical utterances!

• Marcus (1993):– Data of this sort is too weakly probablistic and noisy to

support learning of syntax unless we hypothesize some underlying structure

• But, Farrar (1992): – Found that children were more likely to imitate new

morphemes found in recasts than in other utterances.

Pinker’s (1989) 4 Conditions

• Negative evidence must be present• Negative evidence would have to be useful

to the child• Negative evidence must be used• Negative evidence must be necessary

• Is there evidence for any of these conditions?