- Empty category principle
linguistics, the empty category principle (ECP) was proposed in Noam Chomsky's syntactic framework of government and binding theory. The ECP is supposed to be a universal syntactic constraint that requires traces to be properly governed.
Proper government is defined as follows:
*"A" properly governs "B" iff "A" theta-governs "B" or "A" antecedent-governs "B".
**"A" theta-governs "B" iff "A" governs "B" and "A" theta-marks "B".
**"A" antecedent-governs "B" iff "A" governs "B" and is coindexed with "B".
The ECP is a way of accounting for, among other things, the empirical fact that it is generally more difficult to move up a "wh"-word from a subject position than from an object position.
The intermediate traces must be deleted because they cannot be properly governed; theta-government is impossible because of the position they occupy, Spec-CP; the only possible antecedent-governor might be an overt NP (a wh-word), but the
Minimality Conditionwould always be violated because of the tensed I (which must be present in all matrix clauses), the tensed I would c-commandthe intermediate trace but it would not c-command the wh-word. So we have to say that intermediate traces must be deleted at LF so that they can avoid the ECP.
In the case of object extraction (the trace is a complement of VP), theta-government is the only possible option. In the case of subject extraction (the trace in Spec-IP), antecedent-government is the only possible option.
If the trace is in Spec-IP and we have an overt
complementizer(such as "that"), the sentence is ungrammatical because the ECP is violated. The closest potential governor would be the complementizer, which cannot antecedent-govern the trace because it is not coindexed with it (and theta-government is impossible since trace is in Spec-IP).
For example, in the sentence "Who do you think (that) John will invite?" the ECP works in the following way (the structure is given for the embedded clause only):
*cite book |last=Haegeman |first=Liliane |title=Introduction to Government and Binding Theory| edition=2nd edition| year=1994 | location=Oxford |publisher=Blackwell
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