My question is about similar (for me) question forms "don't I know you" and "do I know you". Is there any difference between them or can they both be used in the same context without any exceptions?

Same question on "Don't you want" and "Do you want".


4 Answers 4


Negative questions are used to express surprise and when we expect agreement from the listener.

Q: Don't I know you? >>> Expected answer: Yes, we've met.

(This is similar to "Haven't we met somewhere before?")

On the other hand, positive questions are really seeking information.

Ex. Why do you keep staring at me. Do I know you?

Finally, you bought tickets to a concert, you know your friend's crazy about the band but she doesn't seem so excited.

Surprised, you ask: "Don't you wanna go?"

  • 5
    Saying "Do I know you?" is not necessarily asking for information. It can imply that the person being accosted doesn't recognize the other person and wishes he or she would simply go away. In other words, it's often used as a politer way of saying "Piss off."
    – Robusto
    Jul 2, 2012 at 15:04
  • Yeah, I thought of mentioning that too
    – Cool Elf
    Jul 2, 2012 at 16:05
  • Is the following helpful?: Don't I know you? means I know you, don't I? while Do I know you? means I don't know you, do I? Jul 4, 2012 at 23:25
  • Hi Stephen. It depends. The second could be a bit different. It states an idea that needs to be confirmed. Normal positive questions (part of the OP's query) are really asking for information, while his "Do I know you?" above is most likely a rhetorical one.
    – Cool Elf
    Jul 5, 2012 at 1:53

Do I know you?

suggests that you think you don't know the person; you are expressing doubt that you know him.

Don't I know you?

suggests that you think you know the person; you are expressing doubt that you don't know him.

  • Is "don't you want" equal to "you want it, don't you" in this case? Jul 2, 2012 at 13:43
  • I'd say that the latter suggests that you think you know the person, but aren't sure, or perhaps forgot their name or where you know them from. You think you know them but can't place them. Jul 2, 2012 at 18:00

The answers above are good. One thing I should mention though is that they most definitely aren't equally polite.

"Don't I know you?" is useful as a way of opening a conversation, as there can now be a (sometimes long) discussion about various things you may have in common. Even if the answer ends up being "no, you don't", you actually will know each other a little by the time the process is done.

By contrast, "Do I know you?" is often used to shut down conversation when someone you don't want to talk to tries to strike up a conversation. Its kind of a rude way to do it, but some folks consider just walking up and talking to someone without an introduction to be rude as well...

  • Thanks for your comment. And which one is more neutral? Jul 2, 2012 at 14:24
  • Let me clarify. As far as "don't I know you" form is more neutral whereas "do I know you" is more negative, will it be correct to use first one when for example someone calls me and I'm not sure if we really know each other (I will surely continue our conversation if I know him, but probably he just called wrong number)? Jul 2, 2012 at 14:35
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    To be safe, I'd use "Don't I know you?", as the other can sometimes be rude. In that situation, "Do I know you?" is kind of an agressive answer, like you are looking for an excuse to tell the person off and hang up. I wouldn't use "Do" unless I was pretty sure it is a solicitation call.
    – T.E.D.
    Jul 2, 2012 at 14:35
  • 4
    It would be odd to use Don't I know you? as a reply to anything: it would normally start a conversation. Do I know you? is neutral when used a start a conversation, but a bit rude or aggressive as a reply, because it is implicitly denying a relationship which the other person has assumed.
    – Colin Fine
    Jul 2, 2012 at 15:12
  • 2
    "Who am I speaking to?" is probably the most neutral possibility there.
    – Colin Fine
    Jul 2, 2012 at 15:54

"Don't I know you?" is used in puzzlement when one is unsure of the "you"'s identity (perhaps it is someone whom one has met before) and indicates a willingness to increase interaction, whereas "Do I know you?" indicates that "you" is someone with whom there seems to be no reason to continue interaction. The latter is challenging: provide your bona fides or get lost, the former more friendly.

  • Very interesting comments on usage examples, they makes it simplier to understand the very difference. Thanks. Jul 2, 2012 at 13:55

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