preposition

In grammar, a part of speech coming before a noun or a pronoun to show a location (in, on), time (during), or some other relationship (for example, figurative relationships in phrases like ‘by heart’ or ‘on time’).

In the sentence ‘Put the book on the table’, on is a preposition governing the noun ‘table’ and relates the verb ‘put’ to the phrase ‘the table’, indicating where the book should go. Some words of English that are often prepositional in function may, however, be used adverbially, as in the sentences ‘He picked the book up’ and ‘He picked up the book’, in which the ordering is different but the meaning the same. In such cases up is called an adverbial particle and the form pick up is a phrasal verb.