Fragment or Missing Comma

A sentence—or independent clause—is complete when it includes a subject and a verb and expresses a complete thought. In contrast, a fragment does not contain a complete thought, even though it may begin with a capital letter and end with a punctuation mark. Often, a fragment is missing a subject, verb, or both.

Here are two examples of fragments:

The last time we went backpacking in the mountains.
Boating around the lake when the storm moved in from the west.

These two groups of words cannot stand alone as complete sentences. They can be corrected in two ways. One way is to attach the fragment to a complete sentence:

I can't remember the last time we went backpacking in the mountains.
The last time we went backpacking in the mountains,
I saw a bear.

Another way to correct fragments is to add a complete subject, a complete verb, or other words that express a complete thought:

We were boating around the lake when the storm moved in from the west.

Although it is sometimes possible for readers to figure out the meaning of a fragment by rereading the sentences that precede and follow it, you don't want to make your reader spend extra time trying to figure out your meaning. Complete sentences usually show the connections between ideas better than sentence fragments do.

Note: Sometimes, a complete sentence may look like a fragment because it is missing a comma after an introductory word group. When you start a sentence with a dependent clause, be sure to use a comma after the dependent clause.

Here is an example of a sentence that looks like a fragment because it is incorrectly punctuated:

Incorrect: If we have enough time this weekend we'll go to see the cherry trees in bloom.

In this sentence, "...we'll go to see the cherry trees in bloom" is an independent clause that could stand alone. "If we have enough time this weekend" is a dependent clause that cannot stand alone. Use a comma to separate the introductory dependent clause from the main clause of the sentence:

Correct: If we have enough time this weekend, we'll go to see the cherry trees in bloom.