Word classes, largely corresponding to traditional parts of speech (e.g. noun, verb, preposition, etc.), are syntactic categories.
In phrase structure grammars, the phrasal categories (e.g. noun phrase, verb phrase, prepositional phrase, etc.) are also syntactic categories.
Dependency grammars, however, do not acknowledge phrasal categories (at least not in the traditional sense).
syntactic categories should not be confused with grammatical categories (also known as grammatical features), which are properties such as tense, gender, etc.
concept used in:
Introduction to Natural Language Processing
University of Michigan
Coursera, October 5 – December 27, 2015
noun & adjective: