Trace (linguistics)
In transformational grammar, a trace is an empty (phonologically null) category that occupies a position in the syntactic structure. In some theories of syntax, traces are used in the account of constructions such as wh-movement and passive. Traces are important theoretical devices in some approaches to syntax.
Concept
A trace is usually what occupies the empty (null) position in the syntactic structure that is left behind when some element undergoes movement. For example, in a case involving wh-movement, a structure like
You like eating what?
is transformed into
What do you like eating?
the wh-word what being moved to the front of the sentence. In theories that posit traces, the position from which the wh-word was moved (in this case, the position of the direct object of eating), is considered to be occupied by a trace. In relevant linguistic texts, the trace may be denoted by a letter t; so the second sentence above may be written:
What do you like eating t ?
Traces are considered primarily in Chomskyan transformational grammar and its various developments. They are distinguished from other empty syntactic categories, commonly denoted PRO and pro. More details and examples can be found in the article on empty categories.
