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Time Noun Phrases
Although in general NPs cannot modify clauses or other NPs, there is a
class of NPs, with meanings that relate to time, that can do
so.20.3 We call this class of NPs
``Time NPs''. Time NPs behave essentially like PPs. Like PPs,
time NPs can adjoin at four places: to the right of an NP, to the
right and left of a VP, and to the left of an S.
Time NPs may include determiners, as in this week in example
((348)), or may be single lexical items as in today in example
((349)). Like other NPs, time NPs can also include adjectives, as in
example ((353)).
(347)0(347
- (348)
- Elvis left the building this week
(348)0(348
- (349)
- Elvis left the building today
(349)0(349
- (350)
- It has no bearing on our work force today (WSJ)
(350)0(350
- (351)
- The fire yesterday claimed two lives
(351)0(351
- (352)
- Today it has no bearing on our work force
(352)0(352
- (353)
- Michael late yesterday announced a buy-back program
The XTAG analysis for time NPs is fairly simple, requiring only the
creation of proper NP auxiliary trees. Only nouns that can be part of
time NPs will select the relevant auxiliary trees, and so only these
type of NPs will behave like PPs under the XTAG analysis.
Currently, about 60 words select Time NP trees, but since these
words can form NPs that include determiners and adjectives, a large
number of phrases are covered by this class of modifiers.
Corresponding to the four positions listed above, time NPs
can select one of the four trees shown in Figure 20.4.
- {Time Phrase Modifier trees: $\beta$Ns, $\beta$Nvx, $\beta$vxN, $\beta$nxN
Determiners can be added to time NPs by adjunction in
the same way that they are added to NPs in other
positions. The trees in Figure 20.5 show that the
structures of examples ((348)) and ((349)) differ only in the
adjunction of this to the time NP in example ((348)).
- {Time~NPs with and without a determiner
The sentence
(353)0(353
- (354)
- Esso said the Whiting field started production Tuesday (WSJ)
has (at least) two different interpretations, depending on whether
Tuesday attaches to said or to started.
Valid time NP analyses are available for both these interpretations and
are shown in Figure 20.6.
& &
- {Time~NP trees: Two different attachments \label{esso
Derived tree structures for examples ((350)) - ((353)), which
show the four possible time NP positions are shown in
Figures 20.7 and 20.8. The derivation
tree for example ((353)) is also shown in
Figure 20.8.
&
&
-.55in
- {Time~NPs in different positions ($\beta$vxN, $\beta$nxN and $\beta$Ns) \label {bearingtrees
- {Time~NPs: Derived tree and Derivation ($\beta$Nvx position)
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XTAG Project
http://www.cis.upenn.edu/~xtag