I'm working on a natural language processing project, and I'm trying to diagram sentence structures as XML.

I've been through this excellent YouTube series: https://www.youtube.com/watch?v=mwDNiZsItbo

As well as a few books and other videos trying to find information on diagramming sentences.

But I keep getting stuck on complex sentences that don't fit the easy "subject -> predicate" mold.

Here's an example, pulled from a random fiction book on my shelf:

"The sound of a helicopter winding up on the cliff cut through the night"

The subject is "sound" modified by "The". The verb is "cut". "The sound cut". That's right (as far as I can tell).

What I'm having trouble with is the sentence complement "Of a helicopter winding up on the cliff"

Because "winding" is being used as a verb here. And I don't know what to do with extra verbs outside of the main predicate.

Can anyone help me determine what it is I'm looking for? I don't know how to start searching for a question like this.

Here's what I have so far:

Diagram of the sentence

I don't know where or how to place "winding up" or "on the cliff"

"On the cliff" is a prepositional phrase that modifies "helicopter" so it can probably go there. But "Winding up" is a verb phrase

EDIT: I know that "on the cliff" is a prepositional phrase. What I don't know is how to deal with a verb that is not a part of the predicate

EDIT 2: I know "to wind" is a verb, but "winding" in its -ing form could be a gerund or an adjective. But it's not. "Winding up" is a verb phrase. (as far as I can tell)

  • 1
    I don't know what you mean by "winding" is being used as a verb here. "To wind" is a verb, and "winding" is its present participle form; in this sentence, it modifies "helicopter". If you're having trouble identifying parts of speech, syntactic relationships, and other properties of sentence elements, then you may get better traction at ELL. Commented Nov 14, 2022 at 1:47
  • In any event, the parse is this: The sound of a helicopter //[that was] winding up on the cliff //cut through the night" The sound of a child /[who was] /crying in the night/ /came through the fog.
    – Lambie
    Commented Nov 14, 2022 at 2:14
  • I'll add that "of a helicopter winding up on the cliff" is a prepositional phrase, so you should probably search for that in your sentence diagramming resources to learn more about how to handle those. (and "on the cliff" is a prepositional phrase within the prepositional phrase... fun!)
    – saritonin
    Commented Nov 14, 2022 at 8:10

2 Answers 2


Here's a slightly simplified tree diagram of the sentence.

enter image description here

Det:determiner / D: determinative / N: noun / PP:preposition phrase

  • What is this style of diagram called? Commented Nov 15, 2022 at 22:08
  • @jordynfinity It's a standard tree diagram. Its main advantage is that it clearly shows the word class (POS) and function of every constituent and how those constituents combine to form a sentence.
    – BillJ
    Commented Nov 16, 2022 at 15:37

Courtesy of the CMU link parser, here is the constituent tree it parsed from your sentence using standard tags:

(S (NP (NP The sound)
       (PP of
           (NP (NP a helicopter)
               (VP winding
                   (PRT up)
                   (PP on
                       (NP the cliff))))))
   (VP cut
       (PRT through)
       (NP the night))

I presume that explains the syntax of your sentence.

  • What does PRT stand for? Preposition? Commented Nov 14, 2022 at 3:07
  • 1
    @HippoSawrUs No, particle.
    – tchrist
    Commented Nov 14, 2022 at 3:35
  • 1
    @HippoSawrUs the PP is the prepositional phrase. The full list of constituent parts is described here: link.cs.cmu.edu/link/ph-explanation.html
    – saritonin
    Commented Nov 14, 2022 at 8:08
  • Thanks for the links. IDK what a particle is; seems like a catch-all. Commented Nov 14, 2022 at 11:22

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.