A subordinate clause (or dependent clause) is a clause that cannot stand alone as a complete sentence because it does not express a complete thought.
Like all clauses, a subordinate clause has a subject and verb.
Examples of Subordinate ClausesHere are some examples of subordinate clauses (shaded). You will notice that none of the shaded clauses could stand alone as a sentence. This is how a subordinate clause (or a dependent clause) is different from an independent clause.
Types of Subordinate ClauseSubordinate clauses can act as adjectives, adverbs, or nouns.
The Adjective Clause. Here is an example of a subordinate clause acting as an adjective:
The Link between a Subordinate Clause and an Independent ClauseWhen a subordinate clause is used as an adjective or an adverb, it will usually be part of a complex sentence (i.e., a sentence with an independent clause and at least one subordinate clause).
The link between a subordinate clause and an independent clause will often be a subordinating conjunction or a relative pronoun. For example:
What is a clause?
What is an independent clause?
What are adjective clauses?
What are adverbial clauses?
What are noun clauses?
What is a subordinating conjunction?
What is a relative pronoun?
Glossary of grammatical terms
COMMAS WITH SUBORDINATE CLAUSES
The big question with a subordinate clause is whether to offset it with a comma (or commas). Here are the general rules:
When the subordinate clause is an adverb
When the subordinate clause starts with a subordinating conjunction (e.g., unless, because, as, until), it will be functioning as an adverb. When the clause starts the sentence, use a comma. If it ends the sentence, do not use a comma. For example (subordinate clauses shaded):
This works for all adverbial phrases. For example (adverbial phrases in bold):
When the subordinate clause starts with a relative pronoun (e.g., which, who), it will be functioning as an adjective. Do not use a comma before your relative pronoun if the clause is essential for meaning. However, do use a comma if the clause is just additional information. For example:
Read more about commas before relative pronouns.
Click on the example with a subordinate clause:
You cannot start a sentence with who or which unless it is a question (i.e., an interrogative sentence). For example: