Adverb Clause
Adverb clauses connect a dependent proposition to a main clause. They differ from adverb phrases because they have clause structure, and they are only one subtype within the broader category of subordinate clauses.
An adverb clause is a subordinate clause that gives an adverbial relationship such as time, condition, reason, concession, or circumstance. It is broader than one conjunction list, and its punctuation depends partly on position and meaning.
Key details
Important caveats
Boundary
Do not label every subordinate clause an adverb clause; relative and nominal subordinate clauses perform different functions.
Further guidance
Diagnostic
Identify the dependent clause, then ask what relationship it adds to the main clause—such as when, why, under what condition, or despite what circumstance.
Punctuation
Introductory dependent clauses often take a following comma in general prose, while clause order and restrictive meaning can affect punctuation choices.
Worked Example
In “Because the server restarted, the job resumed later,” the opening clause gives the reason for the main-clause event, so it functions adverbially.
Sources and evidence
Sources are shown with the role they play in this guide. Historical or style-sensitive claims are kept within the evidence boundary described above.
- Commas After Introductions (opens in a new tab)Purdue Online Writing Lab · Purdue identifies introductory dependent clauses introduced by words such as after, although, because, if, since, until, and when and explains their relation to the main independent clause.
- Clauses (opens in a new tab)Cambridge University Press · Cambridge defines subordinate/dependent clauses as clauses that cannot form sentences on their own and depend on main clauses; they may be finite or non-finite.