next up previous contents
Next: Determiner Conjunction Up: Conjunction Previous: Adjective, Adverb, Preposition and

Noun Phrase and Noun Conjunction

The tree for NP conjunction, shown in Figure 21.2(a), has the same basic analysis as in the previous section except that the <wh> and <case> features are used to force the two noun phrases to have the same <wh> and <case> values. This allows, for example, he and she wrote the book together while disallowing $\ast$he and her wrote the book together. Agreement is lexicalized, since the various conjunctions behave differently. With and, the root <agr num> value is <plural>, no matter what the number of the two conjuncts. With or, however, the root <agr num> is co-indexed with the <agr num> feature of the right conjunct. This ensures that the entire conjunct will bear the number of both conjuncts if they agree (Figure 21.2(b)), or of the most ``recent'' one if they differ (Either the boys or John is going to help you.). There is no rule per se on what the agreement should be here, but people tend to make the verb agree with the last conjunct (cf. [#!quirk85!#], section 10.41 for discussion). The tree for N conjunction is identical to that for the NP tree except for the node labels. (The multi-word conjunctions do not select the N conjunction tree - *the both dogs and cats).
  
Figure: Tree for NP conjunction: $\beta $CONJnx1CONJnx2 and a resulting parse tree
\includegraphics[height=4in]{/mnt/linc/xtag/work/doc/tech-rept/ps/conj-files/betaCONJnx1CONJnx2.ps} \includegraphics[height=4in]{/mnt/linc/xtag/work/doc/tech-rept/ps/conj-files/aardvarks-and-emus.ps}
(a) (b)


next up previous contents
Next: Determiner Conjunction Up: Conjunction Previous: Adjective, Adverb, Preposition and
XTAG Project
1998-09-14