I am doing natural language processing and I am trying to figure out how to parse the following sentence (I am using BNC tags to mark parts of speech):

Have I seen the man?

As far as I see it is like:

Have > VHB
seen > VVN
the > AT0
man > NN1

After that we have:

the + man > np
I > np
have > aux (auxilary verb)
seen > verb

My question is, since sentence should be in form np vp, what is the initial np here? Is it 'Have I'? I do not understand how does 'Have' fit in the whole thing, since it's before the initial np 'I' but should belong with 'seen'.

  • 1
    If you're going for just CFG, there would be no direct link between I and seen; the link would be through Have.
    – prash
    Commented Oct 30, 2013 at 16:27
  • 2
    You'd better come up with a syntax that recognizes more sentence types than np vp. This is a question, which is not a "simple sentence". This sentence has been done things to.
    – jlawler
    Commented Oct 30, 2013 at 20:18
  • I don't understand your POS tags, but as others have pointed out, you've stumbled upon one of the many inadequacies of phrase structure grammars for treating natural language - that is, without introducing transformations. You should read Chomsky '57 'Syntactic Structures'. It's a classic.
    – P Elliott
    Commented Nov 1, 2013 at 2:59

2 Answers 2


The sentence will be a CP in traditional GG: [CP [C have] [IP I seen the man]]. Note that constituent trees represent sentence topology rather than grammatical relations. In the example at hand, "have" and "seen" are coheads but they don't appear contiguously in the sentence.


See Gazdar's 1981 paper on handling questions in a phrase structure grammar for English.

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