I'm looking for an example sentence with a non-projective dependency parse. It doesn't have to be in English, though such an example would be nice.

  • 2
    What are you looking for?
    – dainichi
    May 5 '13 at 15:33
  • 2
    I think you'll have to indicate what you mean by a "sentence with a non-projective dependency parse", because that's not really a standard term, no matter what your professors said. An example would be nice, especially if it contrasted with an example of a sentence that was minimally distinct in that it does have a projective dependency parse, or a non-projective non-dependency parse, or something else that would allow triangulation.
    – jlawler
    May 5 '13 at 16:05

The paper, Non-projective Dependency Parsing using Spanning Tree Algorithms has a few examples of non-projective dependency trees.

non projective tree

Note that dependency graphs are (1) not a formalism and (2) not standardized, so each researcher may re-define what happens in dependencies. Some of those dependency graphs are not even trees. Refer Generating Typed Dependency Parses from Phrase Structure Parses.

dependency graph

  • how do you draw these trees in LaTeX??
    – CpILL
    Jul 13 '15 at 10:50
  • 2
    @CpILL I'm not really big on LaTeX but you can look here: en.wikibooks.org/wiki/LaTeX/Linguistics
    – prash
    Jul 13 '15 at 16:32
  • @prash So the first sentence is non-projective only because of word 'yesterday'?
    – Amir
    Dec 5 '16 at 13:25
  • @Amir: It's a combination of two factors, 'yesterday' and 'which was a Yorkshire Terrier'.
    – prash
    Dec 5 '16 at 16:50

Here's a different way to look at it: you draw the dependency tree above the sentence with each node aligned with the corresponding word in the sentence, draw a line between the words in the tree and their correspondent in the sentence, and check whether there are any lines intersecting.

The structure below is for the French sentence À qui veux-tu que Pierre parle ? (lit. To whom want you that Peter talks?, 'Who do you want Peter to talk to?'). This sentence is non-projective because à qui has sort of "emancipated" from its governor to position itself relatively to veux. The dependency between parle and à crosses three node projections.

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  • Yes, nice example. Feb 18 '15 at 1:12

Here is a short English example from the paper Non-Projective Dependency Parsing in Expected Linear Time:

Dependency tree for an English sentence (non-projective).

Or, if you want it in Universal Dependencies,

Universal Dependencies non-projective tree for an English sentence.

Here is the LaTeX code to generate the latter:

    \begin{deptext}[column sep=1.2em]
        A \& hearing \& is \& scheduled \& on \& the \& issue \& today \\
    \depedge[edge start x offset=-6pt]{2}{7}{nmod}
    \depedge[edge slant=6pt]{4}{8}{nmod:tmod}

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