Embedded Clauses in TAG

Embedded Clauses Matrix Clause Embedded Clause COMP NP VP We think that they have left. COMP NP VP S V S-bar NP VP Embedded Clause

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.

Raising to subject S COMP NP VP COMP It seems that they have left. V S-bar NP VP They seem to have left. COMP VP V VP-bar NP VP 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.

Comparison Second method: First 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 don’t know how to count steps in a derivation.

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.

“Seem” type verbs in TAG VP S John to be happy V AP NP VP Adjunction site 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”.

V VP VP seem S Adjunction site NP VP VP V AP to be happy John

S NP John V VP VP seems S NP VP John to be happy V AP V VP VP seem VP Adjunction VP to be happy V AP This tree shows word order and constituent structure. It also shows that “John” is the subject of “seem.” It doesn’t show that “John” is the subject of “to be happy.”

“Try” type verbs in TAG S S NP VP NP VP TO VP V PRO leave John tried Adjunction site S NP VP TO VP PRO leave S V NP VP John tried Initial Tree Auxiliary Tree These trees show the number of arguments for each verb: “Try” has two arguments. “Leave” has one argument.

S V NP VP John tried S Adjunction site S NP VP TO VP PRO leave

S V NP VP John tried S Adjunction site S NP VP TO VP PRO leave

S NP VP V S NP VP John tried TO VP PRO leave 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 don’t 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 doesn’t require you to disassemble any of the semantic pieces that were already assembled? S V NP VP John tried S NP VP TO VP PRO leave