Government and Binding Theory - Government

The main application of the government relation concerns the assignment of case. Government is defined as follows:

A governs B if and only if

• A is a governor and
• A m-commands B and
• no barrier intervenes between A and B.

Governors are heads of the lexical categories (V, N, A, P) and tensed I (T). A m-commands B if A does not dominate B and B does not dominate A and the first maximal projection of A dominates B. The maximal projection of a head X is XP. This means that for example in a structure like the following, A m-commands B, but B does not m-command A:

In addition, barrier is defined as follows: A barrier is any node Z such that

• Z is a potential governor for B and
• Z c-commands B and
• Z does not c-command A

The government relation makes case assignment unambiguous. The tree diagram below illustrates how DPs are governed and assigned case by their governing heads:

Another important application of the government relation constrains the occurrence and identity of traces as the Empty Category Principle requires them to be properly governed.