Embedded Clauses in TAG

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Embedded Clauses in TAG
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Embedded Clauses
Matrix Clause
Embedded Clause
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Linguistic Background

• Constraints
• Semantic roles

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Embedded Clauses Constraints

• Main verbs are subcategorized for
• The complementizer (that, for, to, etc.)
  Non-finite for-to
• We hoped for there to be no trouble.
• A word at the beginning of a subordinate clause
  that identifies it as a complement
• The morphology of the embedded verb
• Finite present or past tense
• Non-finite infinitive, present participle, past
  participle

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Examples Constraints imposed by the main verb on
the embedded verb

• Say requires a finite embedded clause
• Sam said that Sue saw him.
• Sam said Sue to see him.
• Sam said that Sue seeing him.
• that is a complementizer that goes with finite
  clauses. When it comes after a verb, it is
  optional
• Sam said Sue saw him.
• That he left is a problem.
• He left is a problem.
• That is only optional after a verb.

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Examples Constraints imposed by the main verb on
the embedded verb

• Expect takes a finite clause or an infinitive,
  but not a participle
• We expect to see him.
• We expect that we will see him.
• Modal auxiliary verbs (will, would, may, might,
  can, could, shall, should, etc) are always
  finite.
• We expect seeing him.
• Might sound grammatical because seeing him can
  be a noun phrase, and expect can occur with a
  noun phrase We expect problems
• We expect seen him.

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Finite embedded clauses

• Finite embedded clause
• I believe (that) it is snowing.
• Say, think, scream
• Finite with dummy subject
• It seems that they have left.
• Finite embedded question
• I wondered/asked whether/if it was snowing.
• Finite plus object
• We told them that it was snowing.
• Finite plus PP
• We said to them that it was snowing.

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Non-finite embedded clauses

• Non-finite for-to
• We hoped for there to be no trouble.
• Non-finite Raising to subject
• They seem (to us) to have left.
• Appear, continue
• Non-finite Subject Equi
• They tried to leave.
• Intend, expect, plan, hope
• Non-finite Raising to object
• We believe them to have left.
• consider
• Non-finite Object Equi
• We persuaded them to leave.
• Convince, order, force, signaled
• Non-finite promise
• We promised them to leave.

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English Auxiliary Verbs

• Modal verbs (will, would, can, could, shall,
  should, may, might, and a few others)
• Invariant dont have a third person singular
  form.
• Only occur where you can have present or past
  tense. Dont occur in infinitives, gerunds, or
  participles
• I will go.
• I would go.
• I said I would go.
• I want to can go.
• Compare I want to be able to go.
• Canning go would make me happy.
• Compare Being able to go would make me happy.
• The next verb must be an infinitive without to.
• I will have gone.
• I will be going.
• I will going/gone/went/goes.

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English Auxiliary Verbs

• Have
• Must be followed by a past participle
• I have gone.
• I have going/went/goes/go.
• Progressive be
• Must be followed by a present participle
• I am going.
• I am goes/went/go.
• Passive be
• Must be followed by a passive verb
• The cookies were devoured.
• The cookies were devouring/devours/devour.

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Auxiliary verbs as main verbs(for syntax not
for semantics)

• The auxiliary verb can impose constraints on the
  main verb.
• Sam is sleeping/slept/sleeps.
• The main clause has to be finite (has a tense).
• Sam sleeps/slept.
• Sam to sleep.
• Sam sleeping.
• The auxiliary verb carries the tense, not the
  main verb
• Sam is sleeping.
• Sam be sleeps.

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Summary of constraints on embedded clauses

• The main verb determines the tense and morphology
  of the embedded verb.
• More than one embedded clause
• Each verb determines the tense and morphology of
  the next one
• I think that Sam tried to sleep.
• Think requires try to be finite.
• Try requires sleep to be infinitive.

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The car needs washed.

• In most dialects of English, need takes an
  infinitive as a complement
• The car needs to be washed.
• Sam needs to sleep.
• There are a few verbs that take passive
  participles as complements
• We had them arrested by the police.
• We got them arrested by the police.
• They were arrested by the police.
• They got arrested by the police.
• In Pittsburgh, need and want can take passive
  participles as complements
• The car needs washed.
• Do you want pushed?

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Semantic Roles

• Syntax
• Word order
• Constituent structure
• Constraints agreement, subcategorization, case
  marking
• Semantic roles
• Sue interviewed Sam.
• Sue is the interviewer.
• Sam is the interviewee.

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Semantic Roles in Embedded Clauses

• Sam tried to sleep.
• Sam is the agent of try
• Sam is the agent of sleep
• Sam to sleep is what was tried.
• Sam seemed to sleep.
• Sam is the agent of sleep.
• Sam is not an argument of seem.
• Sam to sleep is the only argument of seem.

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Just the facts

• How many semantic arguments does each verb take
• Try takes two.
• Seem takes one.
• Do the main clause and the embedded clause share
  a subject?
• Yes. Both seem and try share their subjects
  with the embedded verb.

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How we know that the semantic role assignments
are different with Seem and Try

• The cat seems to be out of the bag.
• There seems to be a problem.
• That seems to be my husband.
• The doctor seemed to examine Sam.
• Sam seemed to be examined by the doctor.

• The cat tried to be out of the bag.
• There tried to be a problem.
• That tried to be my husband.
• The doctor tried to examine Sam.
• Sam tried to be examined by the doctor.

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Raising to subject
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S
Two ways to represent that seem and leave
share a subject.
NP VP
V VP-bar
Subj they Verb
seem Complement subj
verb leave
VP
COMP
They seem to have left.
S
NP VP
V S
NP VP
They seem e to have left.
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Comparison

• Second method
• Allow empty strings as terminal nodes in the
  tree.
• An empty string needs to take the place of the
  missing subject of the lower clause.
• The empty string is linked to the subject of the
  main clause to show that the main and embedded
  clauses share a subject.
• The tree represents word order, constituent
  structure, grammatical relations, semantic roles.
• First method
• No empty strings in the tree.
• The tree represents only word order and
  constituent structure.
• Grammatical relations and semantic roles are
  represented in a separate structure.
• Structure sharing in the representation of
  grammatical relations shows that the two verbs
  share a subject.
• Is one method simpler than the other?
• No. Both methods have to represent word order,
  semantic relations, grammatical relations, and
  semantic roles.
• People who argue that one is simpler are usually
  wrong they dont know how to count steps in a
  derivation.

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S
Two ways to represent that try and leave
share a subject.
NP VP
V VP-bar
Subj they Verb
seem Complement subj
verb leave
VP
COMP
They try to leave.
S
PRO is an empty string, but not the same kind of
empty string as e ? Coindexing indicates that
PRO refers to they.
NP VP
V S
NP VP
They(i) try PRO(i) to leave.
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Seem type verbs in TAG
VP
V VP
seem
Auxiliary Tree
Initial Tree
These trees represent the number of arguments for
each verb Seem has one argument, represented
as a VP. To be happy has one argument, John.
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Adjunction
VP
This tree shows word order and constituent
structure. It also shows that John is the
subject of seem. It doesnt show that John
is the subject of to be happy.
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Try type verbs in TAG
Initial Tree
Auxiliary Tree
These trees show the number of arguments for each
verb Try has two arguments. Leave has one
argument.
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Adjunction is only allowed at the top S node so
as not to mess up compositional semantics After
you put together try to leave you dont want to
have to take it apart again by inserting another
verb like expected as in John tried to expect
to leave. Inserting seem into the middle of the
tree doesnt require you to disassemble any of
the semantic pieces that were already assembled?