2. Grammatical Functions and
Thematic Roles
Why do we need thematic roles? To answer this
question, consider (32)—(35) below, all of which
contain the verb smash
1. David smashed the window.
2. The window was smashed by David.
3. A brick smashed the window.
4. David used a brick to smash the window.
grammatical functions of the argument expres-
sions David, the window and a brick are different
in each of the sentences in which they appear,
their thematic roles are the same.
3. Thematic role
, the NP David carries the role of Agent in each
case, despite the fact that it has two different
syntactic functions, namely Subject in (1) and (4),
and Complement of a preposition in (2).
Similarly, in all sentences the NP the window is a
Patient, regardless of the grammatical function it
carries. Finally, the NP the brick carries the role of
Instrument, and appears in two different
functional slots: Subject and Direct Object.
4. Grammatical and semantic function
What these examples clearly show, then, is that
there is no one-to-one relationship between
grammatical function and thematic role, and we
therefore need to distinguish these notions.
grammatical function is primarily a syntactic
notion, whereas thematic roles are primarily
semantic in nature.
5. MODIFICATION & AMBIGUITY
Syntactic trees allow us to capture another
remarkable fact about language. Let’s start with
the following two sentences:
a) The man killed the king with a knife.
b) The man killed the king with the red hair.
(a) meaning “the man used a knife to kill the
king.”
(b) meaning “the king with red hair was killed by the
man.”
6.
7. (a) meaning “the king with the knife was killed by
the man (who
used a gun.)”
b) (
b) meaning “the man used the red hair to kill the
king (perhaps
by strangling him with it.)”
8.
9. These alternate meanings have the exact opposite structures from (a) and
(b). The meaning in (76a) has the PP with the knife modifying king, and thus
attached to the NP:
