Who refers to people, while that and which refer to groups or things. That introduces essential clauses, making the information necessary to understand the sentence, while which introduces nonessential clauses that provide extra, unnecessary information. If that has already been used in a sentence, use which to introduce the following essential clause. If an essential clause begins with this, that, these, or those, use which to connect it. The document provides examples and practice exercises to illustrate the proper uses of who, that, and which.

1. Who vs. That vs. Which

6. PRACTICE Videos: http:// www.youtube.com/watch?v = ifIsgEwwzDU&feature =related http:// www.youtube.com/watch?v = VJbToLgTNwg Exercises: http:// grammar.ccc.commnet.edu/grammar/quizzes/which_quiz.htm