- Head-Driven Phrase Structure Grammar is a constraint-based theory. It uses features and values to model linguistic objects. Values may be complex, e. g. consist of feature values pairs themselves. The paper shows that such feature value pairs together with identity of values and relations between feature values are sufficient to develop a complete linguistic theory including all linguistic levels of description. The paper explains the goals of researchers working in the framework and the way they deal with data and motivate their analyses. The framework is explained with respect to an example sentence that involves the following phenomena: valence, constituent structure, adjunction/modification, raising, case assignment, nonlocal dependencies, relative clauses.
