however, have not supported this suggestion (Bohannon & Stanowicz, 1988;
Bowerman, 1982; Demetras, Post, & Snow, 1986; Hirsh-Pasek, Treiman, &
Schneiderman, 1984; Marcus, 1993). Parental interventions are somewhat ran-
dom, and they often are unrelated to grammar, typically addressing, instead,
matters of pronunciation and factuality.
Anyone who has raised children or spent a great deal of time with children
knows that acquisition depends significantly on a matching procedure. Be-
yond the cooing and baby talk that is part of the bonding that parents and chil-
dren experience, there is a consistent instructional agenda that involves
introducing children to objects in their world and providing them with the
names for those objects. In the case of a ball, for example, a parent will hold
up a ball and utter the word “ball.” Eventually, the day will come when the
child makes his or her first attempt at producing the word, and in most in-
stances it comes out as something other than “ball.” “Ba” is a very common
first effort. Normally, the parent will correct the child’s utterance, stretching
out the word and emphasizing the /1/ sound, and the child will respond by try-
ing his or her best to mimic the parent. This procedure ultimately results in a
close match between the two utterances.^2
Such observations suggest that sociolinguistic conventions play a signifi-
cant role in our understanding of language. The nature of parental interven-
tions, however, are such that they cannot account for the rapid expansion of
grammatical utterances or the fact that 90% of these utterances are grammati-
cally correct by age 3.5.
Overgeneralization of Past Tense. We saw in chapter 5 that formalist
grammars are computational and rule driven. Their treatment of tense illustrates
how the process is understood to work. Formalist grammars propose that regular
past tense is governed by a rule-based submodule. When producing a sentence
likeFred walked the dog,the submodule is activated; it then takes the verb form
to walkfrom the lexicon and applies something like the following rule: “Add the
suffix-edto the untensed verb.” Irregular verbs are handled differently. Between
the ages of 2 and 3, we observe children regularizing irregular verbs by adding
the past-tense suffix. Instead of usingheld,for example, they will produce
holded.After 6 to 8 months, they begin using the irregular forms correctly. The
assumption is that during this period children’s regular tense submodule is
overgeneralizing the rule and that eventually the submodule determines that the
rule does not apply. Pinker (1999) speculated that a second tense submodule, this
one for irregular verbs, is then activated. However, this submodule does not apply
208 CHAPTER 6
(^2) The inability to achieve an exact match results in language change over generations.