That or Which

Before we answer this question, let's speak about what 'that' and 'which' are from the grammatical point of view. This will help us understand how we should use them in a sentence correctly.

So, 'that' and 'which' are relative pronouns and we use them in relative clauses. Let us remind you that a sentence can consist of a main clause and a subordinate clause. The last one can be:

  • a noun clause
  • a relative clause
  • an adverbial clause

Relative clauses can be introduced by relative adverbs (why, where, when) or by relative pronouns (that, which, who, whom, whose).

For example👇

Main clause Relative clause
I saw the woman who bought my car.
I read the book that you recommended.


Now let's make it clear when we can use 'that' and 'which' in a sentence. Look at this table attentively 👇

For people For things
who/that which/that
This is the woman who/that I love. This is the car which/that I bought.


You should remember that we can not omit that/which in the examples given above because they are subjects of the verb. Try to say a sentence without them and you will miss the meaning.

But when that/which are used as objects, we can omit them. 

For example👇

The girl who/that you saw yesterday was my sister. 

The girl you saw yesterday was my sister. (who/that can be omitted)


And the last important thing about the usage of the relative pronouns in a sentence. We do not normally use prepositions before them.

For example👇

The city in which she lives is far from here. (not a usual usage)

The city which she lives in is far away. (usual usage)

The city she lives in is far away. ('which' can be omitted)

Take a quiz 🔥

Choose a proper relative pronoun

1 / 10
His college ____ is very expensive is one of the best in the country.
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