That Allows vs. Which Allows – Which is Correct?
Both “that allows” and “which allows” are grammatically correct, but they serve different purposes. Use “that allows” for essential information identifying which noun you mean, usually without commas. Use “which allows” for nonessential extra information, set off by commas. In formal American writing, this distinction improves clarity and punctuation and reader understanding.
That Allows or Which Allows – Which is Correct?
Both “that allows” and “which allows” are correct. The choice depends on whether the clause beginning with that or which is essential to the meaning of the sentence.
Use “that allows” for a restrictive relative clause. This clause identifies the specific noun being discussed and is not separated from the main sentence with commas.
Use “which allows” for a nonrestrictive relative clause. This clause adds extra information about a noun that has already been clearly identified, so it is normally separated with commas.
In formal American English, that is generally preferred for restrictive clauses, while which is preferred for nonrestrictive clauses. British English and some informal American writing may use which in restrictive clauses, but the comma-based distinction is a reliable choice for clear professional writing.
The Best Trick to Remember the Difference
Use the removal test. Remove the clause beginning with “which allows.” If the sentence still identifies the correct noun and keeps its essential meaning, use “which allows” with commas. If removing the clause makes the meaning unclear or changes which noun is intended, use “that allows” without commas.
For example, in “Choose the program that allows remote access,” the clause identifies the program. Several programs may exist, so the information is essential. In “The program, which allows remote access, is popular,” the program is already identified, and the clause merely adds information.
| Word | Part of Speech | Meaning | Example |
|---|---|---|---|
| that allows | Restrictive relative clause | Identifies the specific noun being described | Use software that allows secure access. |
| which allows | Nonrestrictive relative clause | Adds extra information about an identified noun | The software, which allows secure access, is easy to use. |
How to Use That Allows
Use “that allows” when the following clause is necessary to identify or distinguish the noun before it. Because this is a restrictive clause, do not place a comma before that. The phrase commonly appears in instructions, reports, academic writing, policies, and everyday conversation.
The noun before “that allows” is usually singular, such as system, tool, policy, feature, or method. The verb allows agrees with that singular noun.
Example 1: We need a payment system that allows customers to use digital wallets.
Example 2: Select the setting that allows automatic updates.
Example 3: The agreement includes a provision that allows either party to cancel the contract.
Etymology of the Word That
That comes from Old English þæt, the neuter form of the demonstrative pronoun meaning “that” or “the one.” Over time, it developed several grammatical functions, including demonstrative pronoun, conjunction, and relative pronoun. Its use in restrictive relative clauses is well established in modern English.
How to Use Which Allows
Use “which allows” when the clause provides additional, nonessential information about a noun. The noun should already be specific or identifiable without the clause. In standard formal American punctuation, place a comma before which and another comma after the complete clause when it appears in the middle of a sentence.
“Which allows” can also appear after a comma at the end of a sentence. In that position, the clause explains a result or consequence of the preceding statement.
Example 1: The company introduced a four-day workweek, which allows employees more time for personal activities.
Example 2: She installed a ramp, which allows visitors using wheelchairs to enter the building more easily.
Example 3: The museum extended its opening hours, which allows more people to visit after work.
Etymology of the Word Which
Which comes from Old English hwilc, meaning “of what kind” or “which one.” It developed from a combination of words related to “who” and “like.” Modern English uses which as an interrogative pronoun, a determiner, and a relative pronoun.
Related Concepts
Understanding restrictive and nonrestrictive clauses makes it easier to choose between “that allows” and “which allows.” The key issue is whether the information identifies the noun or simply adds a comment about it.
- Restrictive relative clauses: These clauses provide essential information about a noun. They are not enclosed in commas, and “that” is commonly used in formal American English.
- Nonrestrictive relative clauses: These clauses provide optional information about a noun that is already identified. They are separated with commas, and “which” is generally used.
- Relative pronouns: Words such as that and which introduce clauses that describe or provide information about nouns.
- Subject–verb agreement: The verb allows is singular because its subject is a singular noun. With a plural noun, use that allow or which allow.
- Comma placement: Commas can change whether a relative clause appears essential or optional. Incorrect punctuation may change the intended meaning.
Examples from Media and Literature
Professional writing, journalism, technical documentation, and literature regularly use both constructions. The following examples demonstrate how the meaning changes according to the relative pronoun and punctuation.
- News reporting: “The investigation identified a loophole that allows companies to avoid the new requirement.” The clause identifies the specific loophole.
- Technology writing: “The platform introduced an accessibility feature that allows users to enlarge the text.” The feature is being distinguished from other features.
- Travel reporting: “The city opened a pedestrian bridge, which allows visitors to cross the river safely.” The bridge is already identified, and the clause adds a fact about it.
- Historical writing: “The treaty established a system that allows neighboring states to share water resources.” The clause explains which system the sentence means.
- Literary-style narration: “He carried a small key, which allows him to enter the abandoned library.” The key is already known, and the clause adds a noteworthy detail.
That Allows Synonyms
| Synonym | Definition |
|---|---|
| that permits | Identifies something that gives permission or makes an action possible |
| that enables | Identifies something that provides the ability or means to do something |
| that authorizes | Identifies something that gives official permission |
| that makes it possible to | Identifies something that creates the conditions for an action |
Which Allows Synonyms
| Synonym | Definition |
|---|---|
| which permits | Adds information about something that gives permission or opportunity |
| which enables | Adds information about something that makes an action possible |
| which makes possible | Adds information about something that creates an opportunity |
| thereby allowing | Shows that the preceding action produces an enabling result |
Frequently Asked Questions
Question 1: Is “that allows” grammatically correct?
Yes. “That allows” is correct when the relative clause is essential to identifying the noun. It is normally written without commas, as in “Use the device that allows secure communication.”
Question 2: Is “which allows” grammatically correct?
Yes. “Which allows” is correct when it introduces additional information about an already identified noun. In formal American writing, use commas around the clause when it appears in the middle of a sentence.
Question 3: Can I use “which allows” without a comma?
In some varieties of English, especially British English, “which” may introduce a restrictive clause without a comma. However, formal American writing generally uses “that” for restrictive clauses and reserves “which” for nonrestrictive clauses.
Question 4: Should I write “that allows” or “which allows” after a comma?
Use “which allows” after a comma when the clause adds nonessential information. A comma before “that” is usually incorrect when “that allows” identifies the specific noun being discussed.
Question 5: What is the plural form of “that allows”?
When the preceding noun is plural, use “that allow,” not “that allows.” For example: “Choose the tools that allow faster editing.” The same rule applies to “which allow.”
Conclusion
Both “that allows” and “which allows” are correct, but they are not interchangeable in careful formal writing. Choose “that allows” when the clause identifies the noun and provides essential information. Choose “which allows” when the clause adds nonessential information and should be set off with commas. Pro Tip: Applying this distinction consistently makes professional writing clearer and strengthens your credibility.
