An adverbial phrase usually consists of two or more words: an adverb being the head word in an adverbial phrase plus other words, although it can consist of only one adverb. The adverbial phrase functions as an adverb in a sentence and is often a prepositional phrase that modifies a verb, adjective, or adverb.
Adverb phrases: types and meanings
An adverb phrase can consist of one adverb or an adverb plus other words before it (premodification) or after it (postmodification). Adverb phrases have many different meanings.
In the examples the adverb phrases are in bold. The other words that modify the adverb are underlined
used to give information about
how something happens
where something happens
when something happens
how long something happens
how often something happens
how much or to what degree something happens
certainty or necessity
how certain or necessary something is
the speaker’s opinion of something
the speaker’s perspective or reaction
relationships between clauses and sentences