Clauses  

Clauses are groups of words that contain both a subject and a predicate.

There are two main types of clauses: independent clauses, which can function independently as sentences, and dependent clauses, which depend on an independent clause to form a sentence.

We’ll briefly cover the various types of clauses below. To learn more about how clauses are formed and used, continue on to each individual section.

An independent clause (also known as a main clause) is a clause that forms a complete, independent thought. It does not require anything else to be considered complete, and so it can stand alone as a sentence.

A single independent clause is known as a simple sentence. It contains a subject and a predicate, each of which can have modifiers.

For example:

In each of the above cases, the independent clause remains able to stand alone as a simple sentence.

Sometimes we form a sentence with two (and occasionally more) independent clauses, which is known as a compound sentence. We join the independent clauses together with a comma and a conjunction or a semicolon without a conjunction. For example:

A dependent clause (also called a subordinate clause) is a clause that relies on the information from an independent clause to form a complete, logical thought. As such, it cannot stand on its own to form a sentence.

Dependent clauses are usually marked by dependent words, such as subordinating conjunctions, relative pronouns, or relative adverbs, which link them to independent clauses in a sentence.

For example:

In each of the examples above, the groups of words in bold are clauses, because they each have a subject (I, we, and they) and a predicate (travel, met on the plane, and like to eat sushi). However, we can also see that they are dependent clauses because of their dependent words—whenever, whom and that. Because of this, they cannot stand alone as a sentence; they depend on the information from the independent clauses (in italics) to be logically complete.

Because dependent clauses must be a part of or attached to an independent clause, they serve a variety of grammatical functions depending on what type of dependent clause we are using. There are three primary categories of dependent clauses: noun clauses, relative clauses, and adverbial clauses. We’ll look at a few examples of each. To learn more about them, continue on to the section Dependent Clauses or to the individual sections for each type of clause.

Noun clauses are dependent clauses that function as nouns. Because of this, noun clauses can perform all the roles that a normal noun could play in a sentence, such as the subject of a clause or the object of a verb. For example:

Relative clauses, also called adjective clauses, provide descriptive information about a noun. These clauses can either be essential to the sentence (restrictive clauses) or non-essential (non-restrictive clauses). They are introduced by either a relative pronoun or a relative adverb.

Here are some examples:

An adverbial or adverb clause is used, like a regular adverb, to modify adjectives, verbs, adverbs, and sometimes entire clauses. Adverbial clauses use subordinating conjunctions to connect to an independent clause. For example:

Every clause in English must have both a subject and a predicate. However, when we form imperative sentences to issue commands or requests, the subject is always implied because the sentence is directed at someone specific (either the reader or the person being spoken to). In this case, we never include the subject. For example:

We sometimes include a person’s name to specify who is being addressed, but this is not the same as the subject of the sentence. It is known as a noun of address (also known as a vocative), which is considered parenthetical and set apart by commas. For instance: