That vs. Which
Main DifferenceLike 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.

Difference Between That and Which
That vs. Which
‘That’ and ‘Which’ both are Determiners in English Grammar
That vs. Which
‘That’ is mostly used to introduce a restrictive clause in the sentence; ‘While’ brings in a non-restrictive clause
That vs. Which
The usage of ‘Which’ needs Comma at its foot; ‘That’ does not ask for any punctuation mark
That vs. Which
‘Which’ can form an Interrogative sentence when it is used at the beginning of a sentence; ‘That’ can’t form an interrogative sentence
Thatconjunction
Introducing a clause which is the subject or object of a verb (such as one involving reported speech), or which is a complement to a previous statement.
He told me that the book is a good read.I believe that it is true. — She is convinced that he is British.Whichdeterminer
(interrogative) What, of those mentioned or implied.
Which song made the charts?Thatconjunction
Introducing a subordinate clause expressing a reason or cause: because, in that.
Be glad that you have enough to eat.Whichdeterminer
(relative) The one or ones that.
Show me which one is bigger.They couldn't decide which song to play.Thatconjunction
Introducing a subordinate clause that expresses an aim, purpose, or goal ("final"), and usually contains the auxiliaries may, might, or should: so, so that.
Whichdeterminer
(relative) The one or ones mentioned.
He once owned a painting of the house, which painting would later be stolen.For several seconds he sat in silence, during which time the tea and sandwiches arrived.I'm thinking of getting a new car, in which case I'd get a red one.Thatconjunction
Introducing — especially, but not exclusively, with an antecedent like so or such — a subordinate clause expressing a result, consequence, or effect.
The noise was so loud that she woke up.The problem was sufficiently important that it had to be addressed.Whichpronoun
(interrogative) What one or ones (of those mentioned or implied).
Which is bigger?;Which is which?Thatconjunction
Introducing a premise or supposition for consideration: seeing as; inasmuch as; given that; as would appear from the fact that.
Whichpronoun
(relative) Who; whom; what (of those mentioned or implied).
He walked by a door with a sign, which read: PRIVATE OFFICE.We've met some problems which are very difficult to handle.He had to leave, which was very difficult.No art can be properly understood apart from the culture of which it is a part.Thatconjunction
Introducing a subordinate clause modifying an adverb.
Was John there? — Not that I saw.How often did she visit him? — Twice that I saw.Whichpronoun
Used of people (now generally who, whom or that).
Thatconjunction
Introducing an exclamation expressing a desire or wish.
Whichnoun
An occurrence of the word which.
Thatconjunction
Introducing an exclamation expressing a strong emotion such as sadness or surprise.
Thatdeterminer
The (thing, person, idea, etc) indicated or understood from context, especially if more remote physically, temporally or mentally than one designated as "this", or if expressing distinction.
That book is a good read. This one isn't.That battle was in 1450.That cat of yours is evil.Thatpronoun
(demonstrative) The thing, person, idea, quality, event, action, or time indicated or understood from context, especially if more remote geographically, temporally or mentally than one designated as "this", or if expressing distinction.
He went home, and after that I never saw him again.Thatpronoun
The known (thing); used to refer to something just said.
They're getting divorced. What do you think about that?Thatpronoun
(demonstrative) The aforementioned quality; used together with a verb and pronoun to emphatically repeat a previous statement.
The water is so cold! — That it is.Thatpronoun
(relative) (plural that) Which, who; representing a subject, direct object, indirect object, or object of a preposition.
The CPR course that she took really came in handy.The house that he lived in was old and dilapidated.Thatpronoun
(colloquial) Used in place of relative adverbs such as where or when; often omitted.
the place that [= where or to which] I went last yearthe last time that [= when] I went to EuropeThatadverb
(degree) To a given extent or degree.
"The ribbon was that thin." "I disagree, I say it was not that thin, it was thicker... or maybe thinner..."Thatadverb
(degree) To a great extent or degree; very, particularly in negative constructions.
I'm just not that sick.I did the run last year, and it wasn't that difficult.Thatadverb
To such an extent; so. in positive constructions.
Ooh, I was that happy I nearly kissed her.Thatnoun
(philosophy) Something being indicated that is there; one of those.
Comparison Chart
That | Which |
Type | |
Determiner | Determiner |
Usage | |
Mostly used to introduce a restrictive clause in the sentence. | Brings in a non-restrictive clause. |
Comma | |
Does not need Comma at its foot. | Needs Comma at its foot. |
Lag | |
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’?