English Grammar for the Utterly Confused - Laurie Rozakis 2003
Using Who, Which, That
Chapter 2. Using Pronouns Correctly
Part 1 Welcome to grammarland
Special rules govern the use of the relative pronouns who, which, and that.
1. Who refers to people or animals (only animals with names or special talents, like Lassie). She is not the actress who was originally cast in the role.
2. That and which refer to things, groups, and unnamed animals.
The choice between which and that depends on whether the clause introduced by the pronoun is restrictive or nonrestrictive.
• A restrictive clause is essential to the sentence.
• A nonrestrictive clause adds extra meaning, is set off by commas, and can be removed from the sentence.
Use that for restrictive clauses and which with nonrestrictive clauses.
Once, at a social gathering, Gladstone said to Disraeli, “I predict, sir, that you will die either by hanging or by some vile disease.” (restrictive clause)
Disraeli replied, “That all depends, sir, upon whether I embrace your principles or your mistress.” (restrictive clause)
Postage meters, which are easy to use, are available at the book store. (nonrestrictive clause)
Quick Tip
In spoken English, who and whomever are becoming more and more uncommon. Informally, people use who and whoever in almost all situations.
