For any possible sequence of words, the grammar determines what, if any,
valid phrase structures it has. For example, the expression the kid has exactly
one analysis in this grammar, namely [NP [Det the] [N kid]]. According to this
grammar, the expressions kid the and the dog are also ungrammatical; the former
because there is no rule C → N Det (where C is any category) in the grammar,
the latter because there is no lexical entry for dog. Some expressions have mul-
tiple analyses, such as the classic example saw the kid with the telescope, which
has the two (abbreviated) structures [VP [VP saw the kid] [PP with the telescope]]
and [VP saw [NP [NP the kid] [PP with the telescope]]]. This example contains a
so-called structural ambiguity between the situation in which the prepositional
phrase with the telescope modifies the noun phrase the kid and one in which it
modifies the verb phrase saw the kid.