Grammatical roles

This chapter discusses the core components of a clause that are obligatory, which includes subject, predicate, and object if the clause is transitive. It shows how core components may be added a peripheral noun phrase (pNP), which is in most cases optional. The role of the preposition is to indicate the semantic role of its NP; for instance, whether it refers to an instrument, a purpose, an ability, a location, or any of many other possibilities. The chapter outlines two kinds of pNP that deal with prepositions in their basic spatial or temporal meanings: inner pNP and outer pNP. An inner pNP provides spatial modification of a verb or the meaning of the preposition that correlates with the meaning of the verb, while an outer pNP provides spatial or temporal modification of a complete sentence.