Clause

 

Clause

A clause is a group of words that includes a subject and a verb. (A clause functions as an adjective, an adverb, or a noun.)



A clause contrasts with a phrase, which does not contain a subject and a verb. The distinction between a clause and a phrase is clearer when you see them side by side:

Anna sings...	when she wakes up. (This is a clause. It has a subject ("she") and a verb ("wakes up").)
	in the morning. (This is a phrase. There is no subject and no verb.)

Easy Examples of Clauses

• During the day, Vlad slept in a coffin.
(The subject of this clause is "Vlad." The verb is "slept." "During the day" is a phrase because there is no verb.)
• When the Moon shone, he lurked in the shadows.
(The subject of the first clause is "the Moon." The verb is "shone." The subject of the second clause is "he." The verb is "lurked.")
• He stalked a pretty milkmaid, who lived in the neighbouring village. (The subject of the first clause is "He." The verb is "stalked." The subject of the second clause is "who." The verb is "lived.")

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Real-Life Examples of Clauses

There are two types of clause:

• An independent clause (one that can stand alone as a sentence).
• A dependent clause (one that is usually a supporting part of a sentence).

In these three quotations, the independent clauses are shown in bold and the dependent clauses aren't.

• Even though I made $800 million, I am still grounded. (Boxer Floyd Mayweather)
(The independent clause could be a standalone sentence, but the dependent clause couldn't.)
• A computer once beat me at chess but was no match for me at kick boxing. (Louis Hector Berlioz)
• After I die, I'll be forgotten. (Anon)

The opening words of the dependent clauses above ("Even though," "but," and "After") are all subordinating conjunctions. Subordinating conjunctions link a dependent clause to an independent clause.

How Are Clauses Used in Sentences?

Clauses can play a variety of roles in sentences. A clause can act as a noun, an adjective, or an adverb.

(1) Noun Clauses

• She cannot remember what she said last night.
(The clause acts like a noun. It could be replaced with a noun, e.g., "her rant.")
• Now I know why tigers eat their young. (Mobster Al Capone)
(This clause could be replaced with a noun, e.g., "the reason.")

Read more about noun clauses.

(2) Adjective Clauses

• My friend who lives in London looks like Homer Simpson.
(The clause acts like an adjective. It could be replaced with an adjective, e.g., "my London-based friend.")
• You should never make fun of something that a person can't change about themselves. (YouTuber Phil Lester) (This clause could be replaced with an adjective, e.g., "unchangeable.")

Read more about adjective clauses.

(3) Adverbial Clauses

• He lost his double chin after he gave up chocolate.
(The clause acts like an adverb. It could be replaced with an adverb, e.g., "recently.")
• I am not afraid of the pen, the scaffold or the sword. I will tell the truth wherever I please. (Labour-rights campaigner Mary Harris Jones aka "Mother Jones")
(This clause could be replaced with an adverb, e.g., "there.")

Read more about adverbial clauses.

Why Should I Care about Clauses?

Native English speakers can create and combine clauses and phrases without stumbling into too many snags. However, there are two great reasons to care about clauses.

(1) Understanding when to offset an adjective clause with commas.

The adjective clauses in these two sentences are identical, except one is offset with commas and one isn't. They are both punctuated correctly. So, what's going on?

• A boy who went to my school won the lottery. 
• Michael Carroll, who went to my school, won the lottery. 

Look at the first example. When an adjective clause is required to identify its noun (here, "boy"), then it is not offset with commas. (Put another way, the subject of the sentence is "A boy who went to my school.")

Look at the second example. When an adjective clause is just additional information, then it is offset with commas. (Put another way, the subject of the sentence is "Michael Carroll.") If you'd happily put brackets around the clause or delete it, then it should be offset with commas.

Here are some more examples:

• You went through a phase when you dyed your hair purple.  (There is no comma because the clause is needed to identify the phase. A clause that's necessary for identification is called a restrictive clause.)
• You went through a punk phase, when you dyed your hair purple. 
(There is a comma because the phase has already been identified as the punk phase. The clause is just additional information. A clause that's just additional information is called a non-restrictive clause.)
• You went through a mod phase, when you started school, a punk phase when you dyed your hair purple and a punk phase when you dyed your hair green. 
(The first adjective clause is just additional information (hence the commas), but the other two are required to identify the punk phases (hence no commas).)

Lots of writers fly by the seat of their pants when it comes to commas, and mistakes with commas are extremely common. Therefore, this is a key point for writers. It crops up all the time (especially with "who" and "which"). It is covered again from slightly different perspectives in the entries on adjective clauses, adjective phrases, relative adverbs, relative pronouns, restrictive clauses, and non-restrictive clauses. Don't worry though! It's the same idea across all of these topics:

The Same Idea Every Time
If you'd happily put your clause in brackets or delete it, then use commas because it must be non-essential.

(2) Understanding when to offset an adverbial clause with commas.

The adverbial clauses in these two sentences are identical, except one is offset with a comma and one isn't. They are both punctuated correctly. So what's going on?

• When the game has finished, the king and pawn go in the same box.  (Italian Proverb)
• The king and pawn go in the same box when the game has finished. 

When your adverbial clause (or phrase for that matter) is at the front of a sentence (often called a "fronted adverbial"), it is good practice to use a comma afterwards (as in the first sentence above). When it's at the back, the comma tends to be omitted (as in the second sentence).

This "rule" works well with most adverbial clauses (which tend to be adverbs of time, place, or condition). Look at the commas after the fronted adverbials in these examples:

Adverbial Clauses of Time

• When you win, say nothing. When you lose, say less. (NFL coach Paul Brown)
• Say nothing when you win. Say less when you lose. 

Adverbial Clauses of Place

• Where there are too many soldiers, there is no peace. Where there are too many lawyers, there is no justice.  (Chinese philosopher Lin Yutang)
• There is no peace where there are too many soldiers. There is no justice where there are too many lawyers. 

Adverbial Clauses of Condition

• If you think you can, you can. If you think you can't, you're right.  (Businesswoman Mary Kay Ash)
• You can if you think you can. You're right if you think you can't. 

Key Points

• If your clause is needed to identify your noun, don't offset it with commas.
• The only man who never makes a mistake is the man who never does anything.  (US President Theodore Roosevelt)
• If your clause is just additional information that you'd happily put in brackets or delete, offset it with commas.
• My father, who had previously been a civil engineer, died in the great influenza epidemic of 1918.  (Physicist James Rainwater)
• If your adverbial clause is fronted, use a comma.
• Don't use a comma if your adverbial clause is at the back.