That vs Which
Published January 25, 2023. Updated January 25, 2023.
That and which are similar in function, but they have a few differences. That can be used as a conjunction, determiner, and pronoun whereas which can only be used as a determiner and pronoun.
As a conjunction, that can be used to start clauses that are either the subject or object of a given verb, a subordinate clause that provides a cause for something, or a subordinate clause that shows the consequences of something. As a determiner, that indicates a noun that is not near the speaker either literally or figuratively. As a pronoun, it has the same meaning as its determiner form, but it can also be used to refer to an item just mentioned in the conversation, or it can be used as a relative pronoun to connect a dependent clause to an independent one.
As a determiner, which can be used as a question word that functions like “what” when referring to either an explicit or implicit list of items, whichever, or to refer to an item that was previously mentioned. As a pronoun, it has the same first two meanings of its determiner form, or it can be used as a relative pronoun to connect a dependent clause to an independent one.
Here are some definitions and examples to help make the use of these words clearer.
That (conjunction)
- Starts a clause that is either the subject or object of a given verb. Can sometimes be omitted.
Examples:
She said that she would always hate me for forgetting her birthday.
I thought that we were going to the amusement park today.
- Starts a subordinate clause that provides cause for something.
Examples:
You’re lucky that your dad paid for your college.
The principal was happy that all the students did well on their exams.
- Starts a subordinate clause that shows the consequences of something.
Examples:
You snored so much last night that I couldn’t sleep.
I ate so many slices of pizza that I threw up afterward.
That (determiner)
Indicates a noun that is not near the speaker either literally or figuratively. Must be used with the noun itself.
Examples:
Can you hand me that wrench?
I can’t believe you forgot that time we got grounded for staying out too late.
That (pronoun)
- Indicates a noun that is not near the speaker either literally or figuratively. Must be used in its pronoun form (without the noun).
Examples:
That was so funny.
That is the ugliest baby in the whole tri-state area.
- Used to refer to an item just mentioned in conversation.
Examples:
I broke my boss’s family picture frame. Do you remember that?
I might be going away on a ship for a year. How does that make you feel?
- Used as a relative pronoun to connect a dependent clause to an independent one. See “Should You Use That or Which?” (below) for more details.
Examples:
The movie that you watched last night is on TV again.
The school that has the former actor as a teacher just won an award.
Which (determiner)
- Used as a question word that functions like “what” when referring to either an explicit or implicit list of items.
Examples:
Do you know which classes you’ll take next semester?
Which artist was your favorite from the exhibit?
Examples:
Choose which chair you want for the meeting.
Do you know which class you want for your elective?
- Refers to an item that was mentioned before.
Examples:
I bought a new van, which will be helpful for my landscaping business.
You saw the gorilla yesterday, which will be launched into space next week.
Which (pronoun)
- Used as a question word that functions like “what” when referring to either an explicit or implicit list of items.
Examples:
Do you know which they’ll be showing next week?
Which makes me look best?
2) In place of a previously mentioned noun.
Examples:
Make sure to pack shoes, it doesn’t matter which.
It was either the red or the blue one, I forget which.
3) Used as a relative pronoun to connect a dependent clause to an independent one. See “Should You Use That or Which?” (below) for more details.
Examples:
The sweater, which you love so much, is on the table.
Our neighbor’s car, which has a good sound system, is parked in front of our driveway.
Should You Use That or Which?
For the relative pronoun form, that and which are often used interchangeably in spoken and written contexts in day-to-day English. For the academic or professional form of written American English, though, some grammarians formulated a rule that states that should be used for restrictive clauses (clauses that provide necessary information for understanding a sentence) and which should be used for non-restrictive clauses (clauses that provide unnecessary information).
Restrictive Clause Examples:
The movie that you watched last night is on TV again.
The school that has the former actor as a teacher just won an award.
Non-Restrictive Clause Examples:
The sweater, which you love so much, is on the table.
Our neighbor’s car, which has a good sound system, is parked in front of our driveway.
Main Points
- That and which have many overlapping meanings, although they also have many different uses as well.
- That can be used as a conjunction, determiner, or pronoun while which can only be used as a determiner or pronoun.
- As relative pronouns, some American grammarians prescribe the rule that that should only be used for restrictive clauses, and which should only be used for non-restrictive clauses.