Difference Between That and Which


Main Difference

Like many other words in English Grammar, ‘Which’ and ‘That’ also confuse many learners. It is simply because both these words play almost the same role in introducing additional clauses in a sentence. However, their opting for either of these grammatical words can change the meaning of the sentence. As far ‘Which’ is concerned, it is used in the non-restrictive clause to give more details about the thing talked about in the sentence. On the other hand, ‘That’ is used to introduce a restrictive clause to limit the details. Consider these two sentences: ‘The book that has a red cover is mine’ and ‘The book, which has a red cover, is mine’. The first sentence suggests that the speaker is telling that he has only one book with red color; in the second sentence, however, he is indicating to a particular out of many. A notable difference can be seen in the usage of both these words as Comma is used before ‘Which’, while ‘That’ does not need any punctuation mark. Another thing worth mentioning is that the Determiner ‘Which’ can also form an Interrogative sentence when it starts a sentence e.g. ‘Which way leads to the market’? or ‘Which country has the biggest desert?’ On the other hand, the determiner ‘That’ cannot be used to form an Interrogative sentence and can only be used either as a relative Pronoun, Adjective, Conjunction to introduce a Subordinate Restrictive clause or as a Demonstrative Pronoun at the start of a sentence.

Comparison Chart

Mostly used to introduce a restrictive clause in the sentence.Brings in a non-restrictive clause.
Does not need Comma at its foot.Needs Comma at its foot.
Cannot form an Interrogative sentence.Can form an Interrogative sentence.

Definition of That

‘That’, basically, has multiple statuses in English Grammar just like many other words. It is mostly termed as ‘Determiner’ as it determines or identifies the thing being talked about in a sentence. It is also given the title of as ‘Subordinator’ since it links the Subordinate Clause with the main clause. Besides, ‘That’ is also used as Adjective, Adverb, as well as Relative Pronoun to indicate or relate a particular person or thing. ‘That’ is mostly used with restrictive clauses to limit the meaning of the thing being talked in the sentence e.g. ‘I like to read the book that has changed my life’. And as a Demonstrative Pronoun, ‘That’ indicate a thing or person e.g. ‘I’d like to buy that shirt’, meaning the shirt lying a bit far from the speaker.


Definition of Which

‘Which’ is also having more than one title in English Grammar. Besides being a Determiner, just like ‘That’, it also relates Person or Thing and plays the role of an Adjective as well. ‘Which’ is mostly used in non-restrictive clauses where it needs a Comma to get support from. Though ‘Which’ has almost the same titles as ‘That’ does, it can also be used at the start of a sentence to make it Interrogative e.g. ‘Which cinema do you like to watch a movie in’? or ‘Which film star has won the Oscar this year’?

Differences in a Nutshell

  1. ‘That’ and ‘Which’ both are Determiners in English Grammar
  2. ‘That’ is mostly used to introduce a restrictive clause in the sentence; ‘While’ brings in a non-restrictive clause
  3. The usage of ‘Which’ needs Comma at its foot; ‘That’ does not ask for any punctuation mark
  4. ‘Which’ can form an Interrogative sentence when it is used at the beginning of a sentence; ‘That’ can’t form an interrogative sentence
Aimie Carlson

Aimie Carlson is an English language enthusiast who loves writing and has a master degree in English literature. Follow her on Twitter at @AimieCarlson