Here is a question that has been nagging me for a few years: Which is the right usage: "Didn't used to" or "didn't use to?"

Examples: We lived on the coast for years but we didn't use to go to the beach! We lived on the coast for years but we didn't USED TO go to the beach!

He didn't use to read stories as a child, but he grew up to be a writer. He didn't USED TO read stories as a child, but he grew up to be a writer.

Did you use to play video games in your youth? Did you USED TO play video games in your youth?

I have seen this question asked on many other websites, and there has been a great deal of debate, but it had generally been inconclusive.

I personally consider 'didn't USED TO' a wrong usage, but would like an expert opinion.

  • ell.stackexchange.com would be more suitable for such questions. – olegst Apr 18 '17 at 8:48
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    "He didn't use to ... is correct. The verb is "use" and since the auxiliary "did" requires a plain (infinitive) verb-form, "use" must be correct. "Use" has no present tense form, but the past tense form "used" occurs in examples "He used to smoke" and the odd-sounding "He usedn’t to smoke" and "Used he to smoke"? – BillJ Apr 18 '17 at 9:32
  • @BillJ, my answer was basically wrong, so I just deleted it. It would have to be completely rewritten anyway. Your comments nailed it. Why don't you post it as an answer. – fixer1234 Apr 18 '17 at 9:54
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    @sumelic It's clear from his comment above (which is what I was going on). There's also a tell-tale problem about what the issue is here because Bill says in his post (I'd previously been referring to his comment) that examples (1) and (2) are pronounced the same way. The question is: How would one know? If (1) and (2) are homophonous, how does one know in any given case that someone is saying (1) and not (2)? More importantly, how does one know if everybody is not in fact saying (2) and not (1)? There's a puzzle, innit? – Araucaria - Not here any more. Apr 18 '17 at 21:31

[1] He didn't use to smoke

[2] He didn't used to smoke.

Only [1] is correct. The uncertainty about which form to use probably arises because the "used to" in [2] is pronounced with a single /t/ and hence is homophonous with the "use to" in [1].

[3] He didn’t use to smoke.

[4] Did he use to smoke”?

The aspectual verb "use" has no present tense, only infinitival and past forms, so although the form "use" appears to be a present tense form, it is in fact the plain (infinitive) form which is only used in negatives and with inversion, as in [3] and [4]. Note that the auxiliary verb "do" requires the verb that follows it to be an infinitive, hence "use", not "used".

There is the added complication that "use" can be a lexical verb or an auxiliary one, though the books tell us that most speakers treat it as a lexical one. I suspect that’s due to the unacceptability for many people of the auxiliary use found in %Smoking usedn’t to be allowed and %Used he to smoke?

Lexical Use (negatives and interrogatives require do-support):

[5] He used to smoke.

[6] He didn’t use to smoke.

[7] Did he use to smoke?

Auxiliary Use (do-support not required):

[8] He used to smoke

[9] %He usedn’t to smoke.

[10] %Used he to smoke?


In this context it should be "use to" rather than "used to" since an infinitive is required (Cf. "I didn't cook it" v. "I didn't *cooked it"). The confusion is understandable though since in other situations (e.g. "I used to cook") the final consonant on "used" is all but identical with the initial consonant of following "to" and so will often be assimilated and/or dropped in speech.

  • Thank you for the clarification. As you know, this matter of didn't used to has been generating all sorts of answers for years, and it's good to get a clear, unequivocal reply! – English Student Apr 18 '17 at 12:15
  • How do you know that used isn't the infinitive? – Araucaria - Not here any more. Apr 18 '17 at 21:46
  • Linguistically speaking it may well be: for many speakers there might have been some reanalysis that's gone on such that the idiomatic "use(d) to" has drifted and separated from the lexical verb "use". However, in the standard written language, what I say above is the case and I that's probably the best basic approach to take pedagogically. – Miztli Apr 18 '17 at 21:52

Thanks all for the links and references. One answer that makes a whole lot of sense was given by John Lawler on Oct 31 '13 -- "This is not a language or grammar problem. This has to do with spelling exclusively. Every English speaker knows that the negative of /'yustə/ is /'dɪdən yustə/. That's what's said millions of times daily by English speakers. How you want to spell /'dɪdən yustə/ is what causes all the problems."

I encounter written English FAR MORE OFTEN than the spoken form, and hate to read "didn't used to" on the smartphone. So now I get it: they're just misspelling "didn't use to!"

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    Yes, that's right. One thing not mentioned yet is that "use" can be both a lexical verb and an auxiliary. When used with do-support, it's a lexical verb ("He didn't use to smoke" / "Did he use to smoke?"), but otherwise it's an auxiliary verb ("He usedn’t to smoke" / "Used he to smoke"?). The auxiliary use is rarely heard nowadays. – BillJ Apr 18 '17 at 14:16
  • Very true. I just couldn't understand why the majority of people were writing 'didn't used to' (as in a glaring grammatical error) but your replies have clarified the matter: so it's mostly a misspelling! – English Student Apr 18 '17 at 15:11
  • I've just posted a comprehensive answer about the aspectual verb "use". – BillJ Apr 18 '17 at 15:16
  • People who write didn't used to are not misspelling didn't use to. If we are talking about the auxiliary pronounced yusta, then both ways of writing it look strange. If you read @Lawler's web page, you'll see that he concludes by saying "Basically, this is a bug in English writing. So, the answer is, you pays your money and you takes your choice. There is no correct answer, and opinions differ." – Arm the good guys in America May 3 '18 at 2:58
  • Also, see the Ngram included in this answer. In descriptive linguistics we can't really call something a "misspelling" if that is the way most native speakers spell it. (On the other hand, this answer suffers from calling this popular spelling "ungrammatical.") – Arm the good guys in America May 3 '18 at 3:02

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