Consider the following two sentences:

  • Today I ate a very tasty lunch, and one that was also quite healthy.
  • Today I ate a very tasty lunch, and one which was also quite healthy.

The subordinate clause overall ("and one...") is descriptive, however, the conjunction "that" or "which" mediates a restrictive relation between a preceding noun ("one") and a subsequent qualifier ("was also..."). Notably, without any elements following the preceding noun, the sentence would not be understood as complete.

Which of the two sentences above, if either, is more likely to be preferred for a formal style? Why?

Would the choice be different for a broadly similar structure employing a conjunction of an alternative class (e.g. "or"), rather than the cumulative one chosen for the example (i.e. "and")? For example, consider "You may choose either a tasty lunch, or one...".

Please note, it has been suggested that the broader usage distinction between "that" and "which" commonly propagated in style guides, in which "that" precedes a restrictive clause following a main clause, and "which" similarly precedes a descriptive clause, is an unneeded or unhelpful formalism. Nevertheless, the immediate question shirks the broader debate, assuming that the distinction is desired, and considers how it may be applied most favorably in a more nuanced case.

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    Commented Nov 18, 2022 at 1:51
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4 Answers 4


The type of relative clause for the two examples given is an integrated relative clause - they are not separated by a comma from their antecedent (one in this case) and could not felicitously be so separated. Further, their function cannot be described as supplementary seeing as the sentence would be quite deficient without them.

*Today I ate a very tasty lunch, and one.

Since it is an integrated (some might say restrictive) relative clause, we may use either which or that. This is not controversial.

Though the references of the noun phrases in coordination are assumed to be the same in the example given, they need not be in order for the same analysis to apply.

Today I ate [a very tasty apple], and [one which/that wasn't quite so tasty].

Accordingly, for purposes of investigating the difference in preference between that and which, the following string will do.

, and one which/that was

In the Hansard Corpus (British Pariliament), the ratio is 284 which to 129 that.

In the Corpus of Contemporary American English (academic journal section), the ratio is 1 which to 9 that.

In the Corpus of the Supreme Court of the United States, the ratio is 7 which to 6 that. All of them have the same referent for the two noun phrases in question.

So saying, I do not imply it was necessarily in any sense weak; that fact does, however, help to indicate why the issue of motive was particularly crucial , and one which was central to the trial. (392 U.S. 616)

In that case there was a searching scrutiny of the powers of Congress, and it was held to be competent to establish a new rule of liability of the carrier to his employees; in a word, competent to regulate the relation of master and servant, a relation apparently remote from commerce , and one which was earnestly urged by the railroad to be remote from commerce. (208 U.S. 161)

Although the Central Company may have been injured by the result of this lease, yet that is a misfortune which has overtaken it by reason of the rule of law which declares void a lease of such a nature; and, while the company may not have incurred any moral guilt, it has nevertheless violated the law by making an illegal contract , and one which was against public policy, and it must take such consequences as result therefrom. (171 U.S. 138)

We therefore agree with the court below that 'the change was a substantial and meritorious one , and one which was well worthy of a patent, by reason of the improvement which it produced in the operative effect of the cornsheller.' (151 U.S. 139)

It was a promise which entered into and became one of the terms of the contract , and one which was binding, not only upon the parties, but upon all others who sought to acquire rights in it. (152 U.S. 634)

If offered for the purpose of showing a conspiracy between plaintiff and defendant's agent, Carhart, to defraud the defendant, it is sufficient to say that this would constitute an independent defense , and one which was not set up in the answer and was not admissible under a general denial. (143 U.S. 28)

A more conciliatory mode was preferred , and one which was better calculated to impress the Indians, who were then powerful, with a sense of the justice of their white neighbours. (31 U.S. 515)

The Justice Department explained that the issue of constitutional torts was a controversial one , and one that was not affected by the Court's decision in Westfall, because Westfall was limited to common law torts. (499 U.S. 160)

Congress determined that avoiding bankruptcies was an important social goal , and one that was not automatically outweighed by the goal of protecting the environment. (470 U.S. 116)

This is a lesson of constitutional magnitude , and one that was forgotten during the enactment of the Florida statute. (468 U.S. 447)

The Department thus sought to introduce a qualification as to the significance of 'foreign country' not found in the words of the statute, or in those of the preceding income tax acts, or in departmental regulations under them , and one that was inconsistent with the apparent purpose of the enactment. (285 U.S. 1)

Mr. Ady also made a fine speech , and one that was full of argument and replete with the details of the crime committed, as gathered from the statements of witnesses. (146 U.S. 140)

Viewed in that light, it is impossible to sustain the fifth assignment of error, for the reason that it is shown that the inquiry whether the defendant had made any payment for the insolvent debtors was an important inquiry , and one that was properly submitted to the jury. (95 U.S. 347)

In the News on the Web corpus, the ratio is 70 which to 514 that.

In Wikipedia, the ratio is 27 which to 40 that.

Conclusion: There is no clear preference overall, at least not one which would support a rule one way or the other in generalized 'formal style' English.

  • 2
    However, the OP’s first two examples leave open the question how many lunches were eaten :)
    – Xanne
    Commented Nov 18, 2022 at 10:13
  • Do the statistics represent the usage particular to the examples, involving the integrated clause, or more generally to include the case of that or which mediating directly with the main clause?
    – brainchild
    Commented Nov 18, 2022 at 16:03
  • 2
    @brainchild You'll be infinitely happier if you ignore the stupid scolding which-hunters with their arrant nonsense. They're the same kind of harmful idiots who of old would forbid us from splitting infinitives and ending sentences with prepositions. REAL REFERENCES: 1, 2, 3, 4, 5, 6.
    – tchrist
    Commented Nov 27, 2022 at 1:34
  • 1
    Hmmm: "Since it is an integrated (some might say restrictive) relative clause, we may use either which or that. This is not controversial." <--- This should not be controversial, but unfortunately it is in the sense that it is the subject of controversy because of fetishistic sado-masochists as described by Professor Geoffrey K. Pullum in his famous paper The Usage Game: Catering to Perverts . The fact that the earth is not flat should not be controversial, but ... Commented Nov 28, 2022 at 23:57
  • 1
    You're absolutely right, of course, that it is not controversial amongst serious linguists, though. Commented Nov 29, 2022 at 0:44

That Merriam Webster definition is SO simple:

Use 'which' or 'that' to introduce a restrictive clause, and 'which' to introduce a nonrestrictive clause. So:
The car that I rode in today was blue. The car which I rode in today was blue. [same thing]. Both are restrictive.

However, "The car, which I rode in today, was blue". :) This one is non-restrictive.

  • Today I ate a very tasty lunch and one that was also quite healthy.

  • Today I ate a very tasty lunch and one which was also quite healthy.

  • The very tasty lunch I ate today was also quite healthy.

That example does not lend itself to the restrictive example.

The trick here is to remember this trick: The car, that was in the driveway, was not mine. You can't set off a that clause between commas. That is really all you have to remember and whether you want to set off your which clause with commas.

  • Good comma test. Commented Dec 4, 2022 at 23:35
  • 1
    @YosefBaskin It is, isn't it? It suddenly occurred to me....
    – Lambie
    Commented Dec 5, 2022 at 14:43

In addition to what DW256 has already established (no clear preference between the two), I think it is also important to highlight the ambiguity that comes with the first two sentences. Looking at the sentences plainly, it is not explicitly clear if the writer has eaten one or two lunches. Though, logically, one eats a lunch per day. In formal writing, I believe clarity and conciseness are substantial factors, and so although there's neither anything grammatically wrong with either of the sentences nor is one preferred over the other, these may simply be not appreciated, and their shorter yet clear counterparts would be used:

*Today I ate a very tasty lunch that was also quite healthy.

*Today I ate a very tasty lunch, which was also quite healthy.

I hope this helps.


For everyday conversation, either sentence is grammatically correct. For me, the tone varies from each one. "Today I ate a very tasty lunch that was also quite healthy" sounds slightly more casual than, "Today I ate a very tasty lunch, which was also quite healthy." The difference is not extreme.

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