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There are three basic types of prepositional phrases, and three places at which they can adjoin. The three types of prepositional phrases are: Preposition with NP Complement, Preposition with Sentential Complement, and Exhaustive Preposition. The three places are to the right of an NP, to the right of a VP, and to the left of an S. Each of the three types of PP can adjoin at each of these three places, for a total of nine PP modifier trees. Table 20.1 gives the tree family names for the various combinations of type and location. (See Section 24.4.2 for discussion of the spuPnx, which handles post-sentential comma-separated PPs.)
  position and category modified
  pre-sentential post-NP post-VP
Complement type S modifier NP modifier VP modifier
S-complement Pss nxPs vxPs
NP-complement Pnxs nxPnx vxPnx
no complement Ps nxP vxP
{Preposition Anchored Modifiers


The subset of preposition anchored modifier trees in Figure 20.9 illustrates the locations and the four PP types. Example sentences using the trees in Figure 20.9 are shown in ((355))-((358)). There are also more trees with multi-word prepositions as anchors. Examples of these are: ahead of, contrary to, at variance with and as recently as.

ps/modifiers-files/   ps/modifiers-files/   ps/modifiers-files/   ps/
Pss   nxPnx   vxP   vxPPnx

{Selected Prepositional Phrase Modifier trees: $\beta$Pss, $\beta$nxPnx, $\beta$vxP and $\beta$vxPPnx


[PP with Clove healthy PP], the veterinarian's bill will be more affordable . (Pss20.4)  (355)0(355
The frisbee [PP in the brambles PP] was hidden . (nxPnx)  (356)0(356
Clove played frisbee [PP outside PP] . (vxP)  (357)0(357
Clove played frisbee [PP outside of the house PP] . (vxPPnx) 

Prepositions that take NP complements assign accusative case to those complements (see section 4.4.3 for details). Most prepositions take NP complements. Subordinating conjunctions are analyzed in XTAG as Preps (see Section 16 for details). Additionally, a few non-conjunction prepositions take S complements (see Section 8.8 for details).

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Next: Adverbs Up: Modifiers Previous: Time Noun Phrases
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