Looking at a recent story I had published (notice I could have used ‘that’ in this opening clause), I have to admit I cringed at the first sentence: “I remember the first day that she walked into the office.” There’s that ‘that’ word again. Was it really necessary? I should have just written: “I remember the first day she walked into the office.” We use ‘that’ too often and sometimes mix it with ‘which’. So, which is better? That or which? When should we use either, and can we avoid using either?

Use ‘that’ in a restrictive clause and ‘which’ in a nonrestrictive clause. Got it? Or are you even more confused? Well, a restrictive clause is one ‘that’ can’t be removed from the sentence without changing its meaning.

‘That’ is used to point out things and people, to identify a situation and who or what is involved. For example: “What’s in that jar on the counter?” You could just ask “What’s in the jar on the counter?” But, using ‘that’ makes it more specific, and more easily identified. You certainly wouldn’t say, “What’s in which jar on the counter?” unless, of course, you’re complicating the question entirely and changing its meaning.

‘That’ is more informal than ‘which’ or ‘who’/’whom’. “She picked up the coat that lay on the floor.” Much more direct and informal than “She picked up the coat which lay on the floor.” Although both work; it really depends on what you mean to say.

All this/‘that’ being said, ‘that’, and ‘which’ are easily and frequently overused. “That hairbrush that I was using that time last week is not one that I would ever use again.” Too many ‘that’s’. Much better to write: “The hairbrush I was using last week is not one I’d ever use again.” No ‘that’s’; much cleaner writing and easier for the reader to digest.

How to avoid ‘that’? Use bridge verbs like: ‘say,’ ‘think,’ ‘know,’ ‘claim,’ ‘hear,’ ‘believe,’ etc. “You say that you know him.” How about simplifying and omitting ‘that’ and write, “You say you know him.”

‘Which,’ on the other hand, is quite often used in questions: “Which one do you like best?” And, it’s used in nonrestrictive clauses, often to introduce part of a compound sentence. For example: “People think all I do all day is read. Which is only partially true.” Or, “He appeared more nervous, which was because he was meeting with his partner’s family for the first time.”

And, then there is the type of sentence that might use both ‘that’ and ‘which’: “That which was once written is now a fact.”

If this is all too complicated to digest, then do what I do: read your sentence out loud and ask yourself: “Do I need to use ‘that’?” “Are there too many ‘that’s’?” “Does ‘which’ work better?”

And, if that doesn’t work, ask a professional editor to go over your writing. Just remember, that which is too much is always too much.