Adverb phrases and clauses answer the same questions that
Adverbs do: "How?" "When?" "Where?"
When a group of words NOT containing a subject and verb acts
as an adverb, it is considered an adverbial phrase:
He calls his mother as often as possible.
Take two capsule every four hours when needed.
Infinitive Phrases all have the potential to be adverbial phrases.
An adverbial phrase, therefore, should not be thought of as a
particular part of speech but, rather, as the collective function of
a group of words composed of other parts of speech. That
function would be shown in a sentence diagram by placing the
phrase diagonally under the word or words it modifies.
Budgets have changed in recent years not only to accommodate financial shortfalls but also to
anticipate an even worse economy.
In the diagram above, note how all of the phrases are in service to the idea that budgets “have
changed.” Consequently, they all come under that one verb, in some fashion, and are therefore
In similar fashion, an entire clause--a group of words containing a subject and verb--can begin with a
clauses. The subordinators tend to indicate how, when, where, and sometimes why.
There's no trick to diagramming them. The subordinating conjunction goes on a dashed diagonal line
connecting the verb or verbal to the subordinate adverbial clause: