Propositional attitude verbs (e.g.: want, think, know, hope) are acquired relatively late and it has been argued that the syntactic distribution of the input would be particularly useful for acquiring these verbs (Gleitman 1990, among others). For example, the types of complements that occur with a particular attitude verb can betray both coarse-grained (1) and fine-grained (2) differences in meaning.

(1) Finiteness of complement → representational vs. preferential
a. Mary {wants/thinks} John to go to the store
b. Mary {
wants/thinks} John went to the store

(2) Question embedding → factive vs. non-factive
a. Mary {knows/thinks} John went to the store
b. Mary {knows/*thinks} where John went

Despite a rich literature on the relationship between a verb’s meaning and its syntactic distribution, there is much less work showing that children can use these kind of syntactic differences to learn attitude verbs (Asplin 2002, Harrigan et al 2015, White et al 2014), or that these syntactic differences are even attested in speech to children.

In this talk, I’ll present some evidence that (i) the input does manifest the appropriate syntactic differences to learn even a closely related pair of verbs like "think" and "know", and (ii) there are individual differences in the input that might relate to individual differences in children’s understanding of these verbs.