Which sentence correctly uses a nonessential clause separated by commas?

Which sentence correctly uses a nonessential clause separated by commas?

• A. The report, which was lengthy, was approved.
• B. The report which was lengthy was approved.
• C. The report, that was lengthy, was approved.
• D. The report that was lengthy, was approved.

Answer: (A)

Nonessential information is set off by commas and is usually introduced with which. In this sentence, the extra detail “which was lengthy” can be removed without changing who or what is being talked about, so it should be placed inside commas. That gives: The report, which was lengthy, was approved. Using that instead of which would make the clause essential and would not be separated by commas, changing the meaning. And placing a comma after a nonessential that/which clause or using that with commas around it is not standard. So the correctly punctuated sentence is the one that keeps the extra information between two commas and uses which.

Nonessential information is set off by commas and is usually introduced with which. In this sentence, the extra detail “which was lengthy” can be removed without changing who or what is being talked about, so it should be placed inside commas. That gives: The report, which was lengthy, was approved.

Using that instead of which would make the clause essential and would not be separated by commas, changing the meaning. And placing a comma after a nonessential that/which clause or using that with commas around it is not standard. So the correctly punctuated sentence is the one that keeps the extra information between two commas and uses which.