A prepositional phrase consists of a preposition(in, at, with, for, until, and so on) followed by a noun or a pronoun, which is called the prepositional object.Prepositional phrases often describe time and location, among others.
Examples:
In autumn maple leaves turn red.
Gaitshill is one of the most famous neighborhoods in Boston.
After that, there won't be any more problems.
The house was built by John's grandfather.
Prepositional phrases come at the beginning of sentences, but they may appear in other parts as well.
Remember, the preposition cannot correctly be the subject of a sentence, as in these examples:
In autumn is my favorite season.
Without a pencil is no way to come to a test.
Prepositional phrases with the same meaning as adverb clauses
There are also certain prepositions that have essentially the same meaning as adverb-clause markers but are used before noun phrases or pronouns, not with clauses.
Examples:
He chose that university because of its fine reputation. (because/since it has fine reputation).
The accident was due to mechanical failure. (because/since there was mechanical falure).
Visibility is poor today on account of air pollution. (because/since there is air pollution).
He enjoys motorcycle riding in spite of the danger. (although/even though it is dangerous).
Despite its loss, the team is still in first place. (although/even though it has lost).
Her father lived in England during the war. (when/while there was the war).