I’m studying for a final for my English Linguistics class and going through example sentences that we should be able to draw syntax trees for. The sentence He looked at the dog with one eye was marked as ambiguous. The rules we were given for a generative English grammar are as follows:
Sentence [S] → Noun Phrase (Auxiliary) Verb Phrase
Verb Phrase [VP] → (Adverb) Verb (Prepositional Phrase) (Noun Phrase)
Noun Phrase [NP] → (Determiner/Noun Phrase) (Adjective) Noun (Prepositional Phrase)
Prepositional Phrase [PP] → Preposition Noun Phrase
X Phrase → X Phrase Conjunction X Phrase (X being a placeholder for V, N or P)
X -→ X Conjunction X
In this grammar, variables in parenthesis are optional for the phrase. So for the example sentence I have the tree
(made with http://mshang.ca/syntree/ if you find it helpful)
However, I’m having a hard time working out another tree. The phrase with one eye could either be attached to the dog or else directly to the verb phrase (and thus mean that ‘He’ has only one eye).
It seems to me that in order to represent the second meaning in a syntax tree, VP → V (PP) (PP) would have to be a rule in the grammar.