Unification in phrase structure

Unification Grammars (UGs) still have simple phrase structure rules. So, for example, we have a rule that a sentence can look something like this:

This is a phrase structure rule that says that a VP can have a subject on the left (in English). The sentence will also be a VP because it has the same HEAD feature. Most importantly, the CONTENT of a phrase is the same as the CONTENT of the HEAD daughter. These facts are all handled by simple feature merging.

The important thing for UGs is that CONTENT is carried up the tree through the HEAD. The verb is the HEAD so the sentence has the same CONTENT as the verb.

The CONTENT of a sentence will be the same as the verb’s because their CONTENT is merged.