WHAT IS A CLAUSE?

The Clause

Recognize a clause when you see one.

Clauses come in four types: main [or independent], subordinate [or dependent], relative [or adjective], and noun. Every clause has at least a subject and a verb. Other characteristics will help you distinguish one type of clause from another.

Main Clauses

Every main clause will follow this pattern:

subject + verb = complete thought.

Here are some examples:

Lazy students whine.

Students = subject; whine = verb.

Cola spilled over the glass and splashed onto the counter.

Cola = subject; spilled, splashed = verbs.

My dog loves pizza crusts.

Dog = subject; loves = verb.

The important point to remember is that every sentence must have at least one main clause. Otherwise, you have a fragment, a major error.

Subordinate Clauses

A subordinate clause will follow this pattern:

subordinate conjunction + subject + verb = incomplete thought.

Here are some examples:

Whenever lazy students whine

Whenever = subordinate conjunction; students = subject; whine = verb.

As cola spilled over the glass and splashed onto the counter

As = subordinate conjunction; cola = subject; spilled, splashed = verbs.

Because my dog loves pizza crusts

Because = subordinate conjunction; dog = subject; loves = verb.

The important point to remember about subordinate clauses is that they can never stand alone as complete sentences. To complete the thought, you must attach each subordinate clause to a main clause. Generally, the punctuation looks like this:

main clause + Ø + subordinate clause.

subordinate clause + , + main clause.

Check out these revisions to the subordinate clauses above:

Whenever lazy students whine, Mrs. Russell throws chalk erasers at their heads.

Anthony ran for the paper towels as cola spilled over the glass and splashed onto the counter.

Because my dog loves pizza crusts, he never barks at the deliveryman.

Relative Clauses

A relative clause will begin with a relative pronoun [such as who, whom, whose, which, or that] or a relative adverb [when, where, or why]. The patterns look like these:

relative pronoun or adverb + subject + verb = incomplete thought.

relative pronoun as subject + verb = incomplete thought.

Here are some examples:

Whom Mrs. Russell hit in the head with a chalk eraser

Whom = relative pronoun; Mrs. Russell = subject; hit = verb.

Where he chews and drools with great enthusiasm

Where = relative adverb; he = subject; chews, drools = verbs.

That had spilled over the glass and splashed onto the counter

That = relative pronoun; had spilled, splashed = verbs.

Who loves pizza crusts

Who = relative pronoun; loves = verb.

Like subordinate clauses, relative clauses cannot stand alone as complete sentences. You must connect them to main clauses to finish the thought. Look at these revisions of the relative clauses above:

The lazy students whom Mrs. Russell hit in the head with a chalk eraser soon learned to keep their complaints to themselves.

My dog Floyd, who loves pizza crusts, eats them under the kitchen table, where he chews and drools with great enthusiasm.

Anthony ran to get paper towels for the cola that had spilled over the glass and splashed onto the counter.

Punctuating relative clauses can be tricky. You have to decide if the relative clause is essential or nonessential and then use commas accordingly.
Essential relative clauses do not require commas. A relative clause is essential when you need the information it provides. Look at this example:

A dog that eats too much pizza will soon develop pepperoni breath.

Dog is nonspecific. To know which dog we are talking about, we must have the information in the relative clause. Thus, the relative clause is essential and requires no commas.
If, however, we revise dog and choose more specific words instead, the relative clause becomes nonessential and does require commas to separate it from the rest of the sentence. Read this revision:

My dog Floyd, who eats too much pizza, has developed pepperoni breath.

Noun Clauses

Any clause that functions as a noun becomes a noun clause. Look at this example:

You really do not want to know the ingredients in Aunt Nancy's stew.

Ingredients = noun.

If we replace the noun ingredients with a clause, we have a noun clause:

You really do not want to know what Aunt Nancy adds to her stew.

What Aunt Nancy adds to her stew = noun clause.