A phrase is a group of two or more words that does not contain a subject and a verb working together. There are many types of phrases, including verb phrases, adverb phrases, and adjective phrases.

They cannot just stand by themselves. There is usually only one possibility of preposition which must be used after a particular noun. Occasionally alternatives are possible. But in either event ...

A preposition is a word that tells you where or when something is in relation to something else. Examples of prepositions include words like 'after', 'before', 'on', 'under', 'inside' and 'outside'.