What Is an Adverbial Clause? | Definition & Examples

An adverbial clause is a clause—a group of words with a subject and a verb—that acts as an adverb in a sentence to modify the main clause.

Adverbial clauses are a type of dependent clause (i.e., they can’t stand on their own as a sentence). They typically answer questions such as “when” (e.g., “before I study”), “where” (e.g., “where she used to live”), “how” (e.g., “as you have always done”), and “why” (e.g., “so that we can go swimming”) about the main clause.

Adverbial clause examples
I don’t want to go out until I’ve eaten dinner.

Because the gym was closed, they exercised at home.

May can run as fast as Tina can.

What is an adverbial clause?

An adverbial clause (or adverb clause) is, like all clauses, a group of words containing a subject and a verb. Adverbial clauses act as adverbs in sentences to give more information about the main clause.

Because adverb clauses are dependent clauses (sometimes called subordinate clauses), they must always be connected to an independent clause (or main clause). They are introduced with a subordinating conjunction (e.g., “if,” “because,” “so that,” “unless”).

Adverbial clauses in sentences examples
Ben plays the guitar whenever he has free time.

If Nella doesn’t study, she won’t pass the test.

Adverbial clauses can serve many different functions in a sentence. Some of the most common ones are described in the table below.

Type Function Example
Time Describe when something happens After the rain stops, we will go to the park.
Place Describe where something happens Let’s go where we went last weekend.
Purpose Describe why something happens Ari gave Luc a pen because Luc lost his.
Manner Describe how something happens I ran as if my life depended on it.
Condition State possible outcomes If the coat goes on sale, I will buy it.
Concession State a contrast Even though most people hate it, Jasmine loves black licorice.
Comparison Compare or contrast The teachers complain as much as the students do.

Adverbial clauses vs adverbial phrases

Adverbial phrases are similar to adverbial clauses, but adverbial phrases do not contain a subject and a verb.

Adverbial phrase vs adverbial clause examples
Let’s go to the park after lunch.
Let’s go to the park after we eat lunch.

Kevin sings very badly.
Kevin sings as badly as I do.

Adverbial placement rules

Adverbial clauses can be placed at the beginning, middle, or end of a sentence. When placed at the beginning of a sentence, adverbial clauses (called fronted adverbials) are followed by a comma. When adverbial clauses are placed at the end of a sentence no comma is needed.

Adverbial clause placement examples
When you get a chance, send me that photo.

Send me that photo when you get a chance.

Adverbial clauses can also be placed in the middle of a sentence (typically between the subject and the verb), though this positioning is somewhat uncommon. When an adverbial clause appears in the middle of a sentence, it is set off by commas.

Adverbial clauses in the middle of sentences examples
The computer, as if it had a mind of its own, suddenly turned on.

The students, whenever there is a pop quiz, get very anxious.

Note
There are some exceptions to the guideline that adverbial phrases at the end of a sentence not be followed by a comma. For example, there are a few instances where a comma before “because” is preferred, specifically when “because” is used to introduce a reason that is not essential to the meaning of the sentence.

However, in most instances, adverbial clauses at the end of a sentence should not be preceded by a comma.

Frequently asked questions about adverbial clauses

Are adverbial clauses dependent clauses?

Yes, all adverbial clauses (e.g., “because I am thirsty”) are dependent clauses (that is, they can’t stand on their own as a sentence). There are other types of dependent clauses as well: adjective clauses and noun clauses.

What are the types of adverbial clauses?

Adverbial clauses are often classified based on the role they play in a sentence. Some of the most common categories are:

  • time (e.g., “before the rain starts”)
  • place (e.g., “where the sea meets the shore”)
  • purpose (e.g., “in order to win the race”)
  • manner (e.g., “as if she could fly”)
  • condition (e.g., “if we leave now”)
  • concession (e.g., “although Paris is nice”)
  • comparison (e.g., “as smart as he is”)
What is an introductory adverbial clause?

An adverbial clause is a group of words with a subject and a verb that functions as an adverb in a sentence to modify the main clause (e.g., “until Leo comes back”).

An introductory adverbial clause (sometimes called a fronted adverbial) appears at the beginning of a sentence (e.g., “Until Leo comes back, we won’t be able to start cooking”). Introductory adverbial clauses are always followed by a comma.

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Kayla Anderson Hewitt, MA

Kayla has a master's degree in teaching English as a second language. She has taught university-level ESL and first-year composition courses. She also has 15 years of experience as an editor.