Differences between That and Which
Contents
"That" vs. "Which"[edit]
In English grammar, the words that and which are relative pronouns used to introduce clauses that modify nouns. The choice between them depends on whether the clause is restrictive or non-restrictive.[1][2] A restrictive clause contains information essential to the meaning of the sentence, while a non-restrictive clause provides additional, non-essential information.[3][4] Adhering to this distinction is a convention of formal American English, while in British English, which can sometimes be used for restrictive clauses.[5]
A simple test to determine whether to use that or which is to remove the clause from the sentence.[1] If the core meaning of the sentence changes or becomes unclear, the clause is restrictive and should be introduced by that.[3] If the meaning is preserved, the clause is non-restrictive, provides extra information, and should be introduced by which. Non-restrictive clauses are set off by commas, whereas restrictive clauses are not.[4]
Comparison Table[edit]
| Category | That | Which |
|---|---|---|
| Clause Type | Introduces restrictive (essential) clauses.[3][2] | Introduces non-restrictive (non-essential) clauses.[2] |
| Essentiality | The clause is necessary to identify the noun it modifies and cannot be removed without changing the sentence's meaning. | The clause provides extra information and can be removed without altering the basic meaning of the sentence.[4] |
| Punctuation | Not set off by commas. | Set off from the main sentence by commas. |
| Example (Restrictive) | The car that has a broken headlight is mine. (Specifies which car.) | Not typically used in formal American English. |
| Example (Non-Restrictive) | Not used. | My car, which has a broken headlight, is parked outside. (Adds extra info about "my car".) |
| Regional Use | Preferred for restrictive clauses in formal American English. | Can be used for restrictive clauses in British English, though that is also common.[5] |
Restrictive Clauses[edit]
A restrictive clause, also called an essential or defining clause, limits the noun it refers to and is crucial for the sentence's meaning.[3] Using that introduces information needed to identify the specific noun being discussed.
For example:
- Houses that are built on a floodplain are not insurable.
In this sentence, the clause "that are built on a floodplain" is restrictive. It specifies precisely which houses are not insurable. Removing the clause would incorrectly state that no houses are insurable. Because the clause is essential, it is not separated by commas.[4]
Non-Restrictive Clauses[edit]
A non-restrictive clause, also known as a non-essential or non-defining clause, provides additional information about a noun that is already clearly identified. This type of clause is always set off by commas.
For example:
- My house, which is located downtown, was built in 1920.
Here, the noun "My house" is already specific. The clause "which is located downtown" offers extra detail but is not needed to understand the main point that the house was built in 1920.[4] The clause can be removed without changing the sentence's fundamental meaning: "My house was built in 1920."
References[edit]
- ↑ 1.0 1.1 "grammarly.com". Retrieved November 28, 2025.
- ↑ 2.0 2.1 2.2 "masterclass.com". Retrieved November 28, 2025.
- ↑ 3.0 3.1 3.2 3.3 "grammarly.com". Retrieved November 28, 2025.
- ↑ 4.0 4.1 4.2 4.3 4.4 "quillbot.com". Retrieved November 28, 2025.
- ↑ 5.0 5.1 "thoughtco.com". Retrieved November 28, 2025.
