Notes on computational linguistics.pdf - UCLA Department of ...

Stabler - Lx 185/209 2003
10.3.6 Control verbs
There is another pattern of semantic relations that is actually more common that the raising verb pattern:
namely, when a main clause has a verb selecting the main subject, and the embedded clause has no pronounced
subject, with the embedded subject understood to be the same as the main clause subject:
Titus wants to eat
Titus tries to eat
One proposal for these constructions is that the embedded subjects in these sentences is an empty (i.e. unpronounced)
pronoun which must be “controlled” by the subject in the sense of being coreferential. 47
The idea is that we have a semantic pattern here like this:
control
agent
theme
agent
Titus try −s to PRO praise Lavinia
theme
coreferential, "controlled" pronominal element
We almost succeed in getting a simple version of this proposal with just the following lexical items:
try::=T V want::=T V want::=T +k V
ɛ::D
Notice that the features of try are rather like a control verb’s features, except that it does not assign case to
the embedded object. Since the embedded object cannot get case from the infinitival either, we need to use
the empty determiner provided here because this lexical item does not need case.
The problem with this simple proposal is that the empty D is allowed to appear in either of two positions.
The first of the following trees is the one we want, but the lexical items allow the second one too:
T
t
C
C
CP
C’
DP(0)
D
the
D’
NP
N’
N
student
TP
T
t
T’
DP
t(0)
V
try
v
vP
v
v
T
-s
v’
T
to
V
t
VP
V’
TP
T’
DP
D’
D
vP
V
laugh
v
v’
v
VP
V’
V
t
([],[],the student try -s to laugh):C
[]::=>T C (the student,[],try -s to laugh):T
([],[],try -s to laugh):+k T,([],the,student):-k
-s::v==> +k T ([],try,to laugh):v,([],the,student):-k
([],try,to laugh):=D v
47 For historical reasons, these verbs are sometimes also called “equi verbs.”
218
[]::=>V =D v ([],try,to laugh):V
try::=T V ([],to,laugh):T
to::=v T ([],laugh,[]):v
([],laugh,[]):=D v
[]::=>V =D v laugh::V
([],the,student):D -k
the::=N D -k student::N
[]::D