 For example, the grammatical form of a sentence need not be determined by the linear order of its words. Using brackets to disambiguate, we can distinguish the sentence ‘Mary [saw [the [boy [with binoculars]]]]’—whose direct object is ‘the boy with binoculars’—from the homophonous sentence ‘Mary [[saw [the boy]] [with binoculars]]’, in which ‘saw the boy’ is modified by an adverbial phrase. The first implies that the boy had binoculars, while the second implies that Mary used binoculars to see the boy. Even if this distinction is not audibly marked, there is a significant difference between modifying a noun (like ‘boy’) with a prepositional phrase and modifying a verb phrase (‘saw the boy’). More generally, grammatical structure need not be obvious. Just as it may take work to discover the kind(s) of structure that propositions exhibit, so it may take work to discover the kind(s) of structure that sentences exhibit. And many studies of natural language suggest a rich conception of grammatical form that diverges from traditional views; see especially Chomsky (1957, 1964, 1965, 1981, 1986, 1995). So we need to ask how logical forms are related to actual grammatical forms, which linguists try to discover, since these may differ importantly from any hypothesized grammatical forms that may be suggested by casual reflection on spoken language. Appearances may be misleading with respect to both grammatical and logical form, leaving room for the possibility that these notions of structure are not so different after all.