Question

Which sentence contains a nonessential adjective clause? The coach explained the rules that the officials revised in 2010. The coach who is an expert in the sport explained the revised rules to us. After explaining the rules to us, the coach released us to the field. The officials revised the rules, which the coach explained to us before practice.

Answer 1

The answer is "The officials revised the rules, which the coach explained to us before practice."

Step-by-step explanation:

A dependent adjective clause is a group of words containing a subject and a verb. It offers further description or information - similar to what an adjective does - about a noun or pronoun that was mentioned in the main clause. Nonessential adjective clauses are literally not essential for the main clause to make sense. They merely offer extra information about it. A good way to tell nonessential clauses and essential ones apart is by looking for commas. Essential adjective clauses do not take commas, nonessential ones do - in fact, they must be separated from the main clause by a comma. Something else is that fact that nonessential clauses cannot be introduced with the word "that", but essential ones can.

In the last option, we have the adjective clause "which the coach explained to us before practice" modifying the noun "rules". It is separated from the main clause by a comma and the word "which" cannot be "substituted" by "that" because of such comma. Therefore, we a have a nonessential adjective clause.

Answer 2

The answer to your question would be that the sentence that contains a nonessential adjective clause is the following one: The officials revised the rules, which the coach explained to us before the practice.

Step-by-step explanation:

The sentence above contains a nonessential relative clause introduced by the relative pronoun which. The clause is nonessential because the information it provides is not relevant to complete the meaning of the sentence. If it was removed, the sentence would not be altered (see 1). This is also why the clause is separated from the rest of the sentence with a comma.

1) The officials revised the rules