Select the best word for the blank in the following sentence.
Could you please check those documents ______ I sent you yesterday?

Question

Quizplus · Accepted Answer

"That" is used to introduce essential clauses. An essential clause is needed to make the sentence clear. "That I sent you yesterday" is essential to the sentence, making it the correct answer.
"Which" is used to introduce non-essential clauses. A non-essential clause adds information to the sentence but is not necessary to make the meaning of the sentence clear. Use commas to set off non-essential clauses (They met at Kevin's party, which was last weekend).
"Who" and "whom" refer to people, which is why neither is the correct answer.

Select the Best Word for the Blank in the Following