• an adverbial phrase is a phrase, typically a prepositional phrase, that is used as an adverbial. For example in the sentence:
In the bedroom, Jane found something very surprising.
the prepositional phrase,
in the bedroom
is an adverbial phrase.
• adverbial phrases are a type of adverbial (one of the five basic sentence parts). Although they are usually prepositional phrases they can also be adverb phrases such as very quickly in the sentence Jane left the room very quickly.
• adverbial phrases should be distinguished from one-word adverbials such as quietly in the sentence Jane went down the stairs quietly.
• adverbial phrases should also be distinguished from adverbial clauses such as because she was frightened in the sentence Jane went downstairs because she was frightened.
• generally speaking, it is also important to distinguish adverbials—a type of sentence part—from adverbs, which make up a word class.(For example, the single-word adverbial, quietly as it is used in the sentence above, is an adverbial because of the job it is doing in that particular sentence. However, the word quietly considered apart from its use in any particular sentence is an adverb.