That vs. Which

One thing I have always struggled with figuring out when it is appropriate to write “that” versus “which in a sentence. Every time I am writing an email at work, I always question which one to use. So I decided to find out how to use the two words appropriately. The section on punctuation in the stylebook happened to mention this very topic. I have always used both interchangeably, but now I realize that it is not correct to do this.

As I was reading through the stylebook, I saw this in the essential clauses section. When writing and using an essential clause in a sentence, it is standard in AP style to use “that.” An essential clause would be pertinent to the rest of the sentence. A nonessential clause is not necessary in the sentence, but may provide additional information.

Here are some examples of essential and nonessential clauses using “that” and “which.”

Essential
I remember the first time that we met.
My car that is red is fun to drive.

Non-essential

The cheer squad, which won nationals last year, will begin practice this week.
My sofa, which is getting old, is not comfortable to sit on for long periods of time.

Clauses are considered non-essential when removed from a sentence, the sentence would still have sufficient information, and would not change the meaning of the sentence.

I hope this small tip helps you as you are writing and editing.
Sandy