Are these two sentences equivalent?

You needn't pay at once.

You don't need to pay at once.

If yes, which one would you recommend? Is it an US/GB thing?

  • I think we learned in school they are different, but I forgot what was the difference. I'm curious to know too, so +1
    – Frantisek
    Commented May 20, 2011 at 13:11
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    This question is from May 20, 2011, and has been viewed more than 20,000 times in the past seven years. It's hard to imagine that we would gain any practical benefit from closing it at this point.
    – Sven Yargs
    Commented Jun 1, 2018 at 4:33

5 Answers 5


They are equivalent in meaning; however, the non contracted forms would be

You need not pay at once.
You do not need to pay at once.

I think the first is more common in BrE (though I would request confirmation). The second formation is more common is AmE; however, we would more likely say

You don't need to pay right away.

  • 1
    If the former was more common in BrE it is archaic now - I know not of any person who would speak in such a manner.
    – Andy F
    Commented May 20, 2011 at 13:15
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    It may be archaic for you, @AndyF, it's alive and well for me. But it is true that "need" has been for some while in process of changing from a full auxiliary like "must" into a lexical verb like "want".
    – Colin Fine
    Commented May 20, 2011 at 13:34
  • Perhaps a generational or regional distinction then, @Colin? I know for certain that if I used the construction "You needn't shout" instead of "You don't need to shout" it would be considered rather pretentious. I'm not saying that it's wrong, just that I don't hear many people speak that way from day to day (not that they're necessarily correct either, mind you).
    – Andy F
    Commented May 20, 2011 at 13:44
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    For me, that slightly ironic use in "You needn't shout!" (meaning "please don't shout") is exactly where I would most expect to here "needn't".
    – Colin Fine
    Commented May 21, 2011 at 0:26

I initially just thought needn't is probably more British usage, but that it's becoming increasingly archaic / affected.

So I produced this NGram to support my thinking. Restricting to just American or British doesn't suggest it's much more common in either.

Frankly, I just don't know what to make of this one showing the latest trend.

Nevertheless, I'd still advise OP to use don't need to. I doubt anyone would think that meant he wasn't keeping up with the times.

  • 2
    You can always count on Google to pleasantly surprise you with a new cool service :) Commented May 20, 2011 at 13:37
  • becoming affected? It's sick?? Not too sure I understand what you mean by that sentence... Commented Jul 7, 2014 at 3:37
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    @Alexis: You should get in the habit of googling things like define affected if you don't understand a usage (the second definition there is the relevant one: pretentious and designed to impress). Commented Jul 7, 2014 at 4:17
  • Google does not always give you the right answer! Thank you for taking the time to lighten the meaning in this case. We do not have that meaning in French for the verb "affecter". Commented Jul 7, 2014 at 4:24
  • @Alexis: On reflection I suppose it might not have been obvious to you sense #2 rather than sense #1 (influenced or touched by an external factor) was the one that applied in my usage. It crops up a lot on ELU though, so you'd best remember it! :) Commented Jul 7, 2014 at 4:36

We can both use need not and don't need to. However, if needn't is followed by an object, we must use don't need.

For example : You don't need your coat. It's not cold outside.

"Coat" is an object, so it is wrong to say ,"You needn't your coat".


When the Americans want to express a lack of obligation, they use the helping verb (do) with negative (not) followed by need. Brits drop the helping verb and contract not

You needn't pay at once. Brits

You don't need to pay at once. Americans

that simple

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    Do you have some reference that supports this explanation?
    – Davo
    Commented Nov 14, 2017 at 15:06
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    As a 30-something Brit, nah. "needn't" sounds archaic.
    – AndyT
    Commented Nov 14, 2017 at 15:31
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    @AndyT: As a 60-something Brit, I suggest "archaic" might be a bit strong (though I dissent not from your substantive point - it's at the very least a dated / formal usage today! :) Whatever - I seriously disagree with the conflation of Brits and "old-fashioned" constructions implied by this answer. If anything, I'd say on average AmE tends to preserve older forms more than BrE in natural spoken contexts today. Commented Nov 14, 2017 at 16:48
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    @FumbleFingers - I'd be happy to call it "dated" rather than "archaic", but I stole the word from your own answer... ;)
    – AndyT
    Commented Nov 14, 2017 at 16:54
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    @AndyT: Hoist by my own petard! In my defence, I did try to "hedge" my assertion by saying it was becoming increasingly so, and conflating archaic with affected. Mind you, if this question had been asked today, I'd have voted to migrate to English Language Learners rather than posting an answer here. Commented Nov 14, 2017 at 17:27

They are not equivalent.

You needn't pay means that you paid and you're sorry you did.

You don't need to pay mean that you didn't pay and don't have to.

  • 2
    That's wrong actually. You needn't have paid (payment was unnecessary) You didn't need to pay (payment was not necessary)
    – Mari-Lou A
    Commented Nov 19, 2018 at 14:42

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