Language

1.1. What gahl and garnsey (2004) show

There is widespread consensus that one of the tasks of a grammar is to describe the form of language. What Gahl and Garnsey (2004; henceforth G&G) show is that the description of both /t,d/-deletion and word and pause durations in American English needs to make reference to statements of the form ‘such-and-such a syntactic configuration has such-and-such a probability of occurrence in this context’. Therefore, in order to account for the form of language, the grammar needs to include probabilities. In particular, we argue that verb subcategorization probabilities, or verb biases, must be part of the grammar, since the match or mismatch between verb bias and syntactic context affects form.

In a critique of G&G, Newmeyer (2006; henceforth N) agrees that the description of /t,d/-deletion and of other aspects of pronunciation reflects probabilities. However, N argues that the relevant probabilities are ‘extra-grammatical’: ‘generalizations about usage lie outside of grammar per se’ (N, p. 2). We acknowledge that subcategorization probabilities are a function of usage—they are that by definition, in fact. But the fact that subcategorization probabilities are ultimately the result of language use is not at issue. What is at issue is whether speakers know subcategorization probabilities as part of their knowledge of grammar. To establish that this is the case, G&G provided evidence suggesting that subcategorization probabilities affect language form even in situations where only syntactic probabilities, not meaning biases, can guide language production.

In the discussion to follow, we first clarify a point about the experiment reported in G&G and briefly comment on N’s suggestions for future research on this issue. We then compare N’s meaning-based account of verb bias to the notion of syntactic probability in G&G and show that the latter correctly predicts facts about language production and comprehension that are unexplained under N’s account. Finally, we consider N’s suggestions for future research in more detail, arguing that the suggested research cannot shed any light on the issue at hand.

1.2. Controlling for meaning

Reiterating a point made in Newmeyer 2003, following Lavandera 1978, N draws attention to the following fact: sentences with different syntactic structures differ in referential meaning, whereas phonological variants generally do not. As a result, any distributional differences among syntactic variants may result from meaning differences, rather than reflecting stochastic information in the grammar. For example, sentences in which a given verb, say, confirm, takes a direct object (they confirmed the date ahead of time) vs. a sentential complement (they confirmed the date was correct) differ in meaning, and hence observations about these sentences cannot be used as an argument for stochastic grammar. N argues on this basis that G&G1s argument is flawed. But it is N’s critique that is flawed here: G&G did not compare direct object (DO) sentences with sentential complement (SC) sentences. [End Page 405] Doing so would indeed have made us vulnerable to the objection raised by Lavandera. Instead, we compared sentences with high-probability DOs to those with low-probability DOs, as well as high-probability SCs to low-probability SCs. The linguistic fact that allowed us to make this comparison was that particular syntactic contexts have different probabilities of occurrence following different verbs, depending on the verbs’ bias. We compared the aggregate of high vs. low probability sentences within each type (DO or SC). We arrived at generalizations about pronunciation that pertained to sentences of a given type and a given probability, regardless of lexical content. In other words, verb biases allowed us to manipulate probabilities while keeping syntactic structure constant, thus isolating effects of probabilities from those of syntactic structure. We believe that N appreciates the fact that G&G studied phonological variation, not syntactic variation. However, an informal small-sample survey reveals that readers of N’s remarks nevertheless walk away with the impression that G&G compared DO and SC complements to one another.

Oddly, the studies N suggests...