Adverb clauses modify verbs, adjectives, or other adverbs, usually answering one of these questions: When? Where? Why? How? Under what conditions? To what degree? They always begin with a subordinating conjunction such as after, because, if, since, until, or when.
When did the hikers prepare camp? When the sun went down.
Under what conditions would Laurabeth have made the team? If she hadn't broken her ankle.
Words that introduce subordinate clauses
Exercises:
Subordinate clauses 1
Subordinate clauses 2
Subjects of subordinate clauses
Phrases and clauses