coordinate conjunction (C), determiner (D), interjection (I), noun (N), particle (Par), pronoun (Pr), subordinate conjunction (Sub), verb (V), etc. The lexical categories that a given grammar assumes will likely vary from this list. Certainly numerous subcategories can be acknowledged. For instance, one can view pronouns as a subtype of noun, and verbs can be divided into finite verbs and non-finite verbs (e.g. gerund, infinitive, participle, etc.). The central lexical categories give rise to corresponding phrasal categories: Phrasal categories Adjective phrase (AP), adverb phrase (AdvP), adposition phrase (PP), noun phrase (NP), verb phrase (VP), etc. In terms of phrase structure rules, phrasal categories can occur to the left of the arrow while lexical categories cannot, e.g. NP → D N. Traditionally, a phrasal category should consist of two or more words, although conventions vary in this area. X-bar theory, for instance, often sees individual words corresponding to phrasal categories. Phrasal categories are illustrated with the following trees: The lexical and phrasal categories are identified according to the node labels, phrasal categories receiving the "P" designation. Lexical categories only Dependency grammars do not acknowledge phrasal categories in the way that phrase structure grammars do. What this means is that the interaction between lexical and phrasal categories disappears, the result being that only the lexical categories are acknowledged. The tree representations are simpler because the number of nodes and categories is reduced, e.g. The distinction between lexical and phrasal categories is absent here. The number of nodes is reduced by removing all nodes marked with "P". Note, however, that phrases can still be acknowledged insofar as any subtree that contains two or more words will qualify as a phrase. Lexical categories vs. functional categories Many grammars draw a distinction between lexical categories and functional categories. This distinction is orthogonal to the distinction between lexical categories and phrasal categories. In this context, the term lexical category applies only to those parts of speech and their phrasal counterparts that form open classes and have full semantic content. The parts of speech that form closed classes and have mainly just functional content are called functional categories: Lexical categories Adjective (A) and adjective phrase (AP), adverb (Adv) and adverb phrase (AdvP), noun (N) and noun phrase (NP), verb and verb phrase (VP), preposition and prepositional phrase (PP) Functional categories Coordinate conjunction (C), determiner (D), negation (Neg), particle (Par), preposition (P) and prepositional phrase (PP), subordinate conjunction (Sub),