The Ultimate Guide to Understanding the Difference Between "That" and "Which"

When it comes to writing, using the correct grammar is crucial to ensure that your message is conveyed effectively. Two commonly confused words in the English language are "that" and "which," particularly when used in relative clauses. In this blog post, we will explore the difference between "that" and "which" in relative clauses and how to use them correctly.

First, let's define what a relative clause is. A relative clause is a type of dependent clause that provides additional information about the subject of the main clause. It usually begins with a relative pronoun such as "that," "which," "who," "whom," or "whose." For example, "The book, which was written by Stephen King, is a bestseller."

Now, let's delve into the difference between "that" and "which" in relative clauses.

"THAT" IN RELATIVE CLAUSES

"That" is a restrictive relative pronoun. It is used to introduce a clause that is essential to the meaning of the sentence. In other words, the information in the relative clause is necessary to identify the subject of the main clause. For example, "The car that I bought yesterday is red." In this sentence, the relative clause "that I bought yesterday" is essential to identifying which car is being referred to. Without the relative clause, the sentence would simply read "The car is red," which is too vague and could refer to any car.

"That" is typically used with a subject, but it can also be used with an object. For example, "The cake that I baked yesterday was delicious." Here, the relative clause "that I baked yesterday" is essential to identifying which cake is being referred to.

"WHICH" IN RELATIVE CLAUSES

"Which" is a non-restrictive relative pronoun. It is used to introduce a clause that provides additional, non-essential information about the subject of the main clause. In other words, the information in the relative clause is not necessary to identify the subject of the main clause. For example, "The car, which I bought yesterday, is red." In this sentence, the relative clause "which I bought yesterday" provides additional information about the car but is not essential to identifying which car is being referred to.

"Which" is typically used with a comma to set off the relative clause from the main clause. For example, "The cake, which I baked yesterday, was delicious." Here, the relative clause "which I baked yesterday" provides additional information about the cake but is not essential to identifying which cake is being referred to.

COMMON MISTAKES

One common mistake people make is using "which" instead of "that" in a restrictive relative clause. This is incorrect because "which" is a non-restrictive pronoun and does not introduce essential information about the subject. For example, "The car, which I bought yesterday, is red" is incorrect if the intention is to identify a specific car. It should be "The car that I bought yesterday is red."

Another common mistake people make is using "that" instead of "which" in a non-restrictive relative clause. This is incorrect because "that" is a restrictive pronoun and introduces essential information about the subject. For example, "The cake that I baked yesterday, was delicious" is incorrect if the intention is to provide additional, non-essential information about the cake. It should be "The cake, which I baked yesterday, was delicious."

TIPS TO REMEMBER

1. Use "that" in a restrictive relative clause when the information is essential to identifying the subject of the main clause. In other words, the information in the relative clause is necessary to the meaning of the sentence.

Example: The car that I bought yesterday is red.

2. Use "which" in a non-restrictive relative clause when the information is not essential to identifying the subject of the main clause. In other words, the information in the relative clause is additional or non-essential.

Example: The car, which I bought yesterday, is red.

3. Use a comma before "which" when it is used in a non-restrictive relative clause.

Example: The book, which was written by Stephen King, is a bestseller.

4. Do not use a comma before "that" when it is used in a restrictive relative clause.

Example: The person that I saw at the store was my neighbor.

5. Remember that "that" is typically used with a subject, but it can also be used with an object.

Example: The cake that I baked yesterday was delicious.

6. Remember that "which" is a non-restrictive pronoun and does not introduce essential information about the subject.

Example: The cake, which I baked yesterday, was delicious.