Main Which vs. That Takeaways:
- Use that in defining clauses. These are essential to the sentence because if you remove this kind of clause, the meaning of the sentence changes.
- Use which in non-defining clauses. These are not essential to the sentence because if you remove this kind of clause, the meaning of the sentence doesn’t’ change.
- Commas usually offset non-defining clauses.
- Use the mnemonic “sandwich crusts aren’t essential” to remember that “which” and non-defining clauses go together.
What is the Difference Between Which and That?
Use that to indicate something specific. It usually introduces a defining clause that doesn’t need commas. On the other hand, use which to add more information about something specific. It usually introduces a non-defining clause that requires a comma before which and after the last word in the clause.
What is the Rule for Using That or Which?
Here is a quick and easy rule for using that or which correctly: if you remove the clause and the meaning of the sentence changes, use that without commas. If you remove the clause and the meaning of the sentence doesn’t change, use which with commas.
Let’s apply this rule for using which vs. that with our apple examples:
When to use That
The example above contains a defining clause. The phrase “that have a wormhole” defines exactly which apples I’m talking about.
To confirm that this phrase is a defining clause, try removing it from the sentence:
The meaning of the sentence changed.
For example, instead of talking about apples with wormholes specifically, I might be talking about apples in general. Without this defining clause, it’s not clear.
Therefore, we confirmed that this is a defining clause. And as a result, that is the correct word to use.
When to use Which
Conversely, the example contains a non-defining clause. The phrase “which are my favorite fruit” does not define which apples I’m talking about.
Instead, it gives additional information about apples in general.
Let’s confirm this phrase is a non-defining clause by removing it from the sentence. The sentence should still make perfect sense without it.
And it does. Without this phrase, the sentence still makes perfect sense. Therefore, which with commas is the correct choice here.
Examples of Which vs. That in a Sentence
In this example, “that has bad breath” is a defining clause because it’s defining something about the dog.
The writer may have several dogs, but he or she is specifically talking about the one that has bad breath. That is the right choice in this case.
Here, we know “that are hybrid” is an essential phrase. Without it, the phrase “cars use less fuel” has a different meaning.
Since “that are hybrid” is a restrictive clause, we’re right to introduce it using that.
Tara’s shoes are bright green, whether we know that she bought them on vacation or not.
That means “which she bought while on vacation” is a nonrestrictive phrase, and which is the correct word to use.
While it’s interesting to know where the author found the nail, it’s not essential.
If you omit “which was left outside a construction site,” the meaning of the sentence remains. Which is the right choice.
Using That vs. Which With Prepositions
Sometimes you may see that or which paired with another introductory word. The same rules apply even if that or which follows a preposition, such as by, for, or on.
Another Trick to Remember That vs. Which: The “Sandwhich”
When I was a kid, I wasn’t a big fan of crusts. Whenever I made a sandwich, removed the crust from the bread.
As an adult, I’ve made peace with crusts, but they still help me remember how to use that vs. which in a sentence.
If you remove the sandwich crusts, the core of the sandwich doesn’t change. It’s still a sandwich and probably still delicious.
Similarly, if you remove the which clause, the core of the sentence doesn’t change. You’ve might lose little a little bit of detail, but the meaning stays the same.
What’s more, commas usually contain a nonessential or non-defining clause. Think of these commas as the bread on either side of the which clause sandwich.
Therefore, just associate which with sandwich to easily remember when to use which.
There are many ways to use which or that in a sentence. The important thing is to be sure you’re using them correctly. That means sticking to which when you have a nonessential or nonrestrictive clause and using that for essential or restrictive clauses.
If ever you’re not sure whether to use which vs. that, remove the clause and see if the meaning of the sentence changes.
- Did the meaning change? Then use that.
- Is the meaning the same? Then use which with commas.
Is it Which or That? Test Your Knowledge!
Which vs. That Question #1
The answer is FALSE. Use “which” for non-defining clauses and “that” for defining clauses.
That vs. Which Question #2
The answer is D. An essential clause is also called a defining or restrictive clause.
That or Which Question #3
The answer is B. Since “make her cry” is essential to the sentence’s meaning, use “that.”
Which or That Question #4
The answer is A. Since “made her cry” is not essential to the sentence’s meaning, use “which.”
Which or That Question #5
The answer is A. This is a reminder that “which” and nonessential clauses go together.