That versus Which
From TCPwiki
From Main Page / Technical Writing
|
That and which are often confused. Be sure to use the appropriate word.
That
That introduces a restrictive clause, which is a clause that is essential for the sentence to make sense. A restrictive clause often defines the noun or phrase preceding it and is not separated from it by a comma. In general, do include the word that in restrictive clauses, even though in some clauses the sentence may be clear without it. Including that prevents ambiguity and helps translators understand the sentence.
Correct
- You will need to supply information about applications that you want to run with Windows.
Incorrect
- You will need to supply information about applications which you want to run with Windows.
- You will need to supply information about applications you want to run with Windows.
Which
Which introduces a nonrestrictive clause, which is a clause that could be omitted without affecting the meaning of the sentence. It is preceded by a comma. Nonrestrictive clauses often contain auxiliary or parenthetical information.
Correct
- Your package contains the subsidiary information card, which you can use to obtain device drivers or local technical support.
Note
Do not use that or which to refer to a person; instead use who.
