TSA CBT Practice Test

Which of the following sentences uses a nonrestrictive clause correctly?

1. The dog that barks loudly is annoying.

2. The dog, which barks loudly, is annoying.

3. The dog that is brown is mine.

4. The dog that runs fast is winning.

The correct answer is: The dog, which barks loudly, is annoying.

The correct use of a nonrestrictive clause is demonstrated in the sentence where "which barks loudly" is set off by commas. A nonrestrictive clause provides additional, non-essential information about a noun; in this case, it adds detail about the dog without defining or restricting which dog is being discussed. The primary subject of the sentence is understood to mean any dog, and the additional detail about barking is simply supplementary information. In contrast, the other sentences utilize restrictive clauses, which are integral to the meaning of the sentence since they specify which dog is being referred to. Thus, they do not correctly illustrate the use of a nonrestrictive clause.