(1) Does he not know?

(2) Doesn't he know?

I don't usually see and hear questions formed in the first style. I was even surprised to know that it is grammatically correct. And actually it is the most "proper" way to form an interrogative sentence. Ngram shows that the first style was much more popular before than now.

What are your suggestions on choosing between these styles? And I will probably add the third one.

(3) He does not know?


The answers have explained how to form a question, but have not actually provided an account on the usage of the first two forms. Especially I'm interested in the first form: does it sound formal, is it used in speech or only in writing, et cetera.

  • 1
    Ngrams expands "Doesn't he know?" to "Does not he know?", despite the fact that the second form is not used much and is generally considered ungrammatical. You can't trust Ngrams here. "Does not he know?" actually appears relatively commonly in 19th century literature, but I suspect that was because contractions were avoided then in written language, and that it usually represents a spoken "Doesn't he know?". Commented Mar 21, 2014 at 21:03
  • 1
    So you are really asking about when to use contracted negatives? I'd say you simply use "doesn't he know" when you would use "he doesn't know", and you use "does he not know" when you would write "he does not know". But that has little to do with question sentences.
    – oerkelens
    Commented Mar 23, 2014 at 12:54
  • "If you tickle us, do we not laugh?", in a well known play by Shakespeare.
    – QuentinUK
    Commented Mar 26, 2014 at 18:16
  • Well, the question was quite different when I answered it. It asked about "Does he not know?" versus "Does not he know?", and the main difference between these is that the latter is ungrammatical.
    – user230
    Commented Mar 27, 2014 at 5:04

5 Answers 5


The basic (declarative) sentence is:

He does not know.

You can turn this into an interrogative clause with subject-auxiliary inversion. Just switch he and does:

Does he not know?

You can optionally replace does not with doesn't in the original sentence, using the suffix -n't rather than the word not:

He doesn't know.

Now the auxiliary is the single word doesn't, so if we apply subject-auxiliary inversion, we get:

Doesn't he know?

Lastly, you can turn the original sentence into a question by using rising intonation at the end, which you indicate in writing by replacing the period . with a question mark ?:

He does not know?

However, this is only appropriate in certain situations, for example as an echo question—repeating what you heard as a question to express incredulity or to confirm that you heard the speaker correctly. Most (but not all) situations where this would be appropriate are informal, and as a result "He does not know?" sounds somewhat unusual. Instead, you can use the contracted form:

He doesn't know?

But most of the time the interrogative form is more appropriate.


Actually, does not he know sounds strange, but when you use contraction, doesn't he know sounds perfectly fine.

It seems that when forming a question from a negative sentence, we do move the verb, but normally we do not move the not of the negation:

He does not know > Does he not know?
She does not play > Does she not play?
I do not read a lot > Do I not read a lot?

However, when we use a contraction to form the negative, the not gets "reunited" with the verb that it negates:

He doesn't know > Doesn't he know?
She doesn't play > Doesn't she play?
I don't read a lot > Don't I read a lot?


"Does he not know?" is current usage. This is a bit counterintuitive, given that "Doesn't he know?" deconstructs to "Does not he know?" which of course isn't "correct". But that's English. :)

As Maulik says: "She doesn't know?" is a declarative question. It is often used to convey a strong expression of surprise. For example, suppose you had heard that your best friend had gotten a new girlfriend. You were getting together with them to meet her for the first time. It turns out that the girlfriend is your cousin's ex-wife; the divorce went through just a week ago. The conversation might go something like this:

You: She's your girlfriend?
Best Friend: Yep.
You: Seems a little early for you to be dating my cousin's ex-wife, since she only got divorced a week ago. How long have you been dating?
BF: She's your cousin's ex-wife?
You: Yes. You didn't know?
BF: No, I didn't know. (to girlfriend) And you only got divorced last week? Why didn't you tell me?
You (interrupting, to GF): You didn't tell him?
GF: It's complicated...

They are expressing surprise to the point of incredulity about the situation.


When you get confused, a good clue will be how a question tag is formed.

He does know, doesn't he? OR He knows, doesn't he?

Also, the contraction is doesn't. So, my vote goes to...

Doesn't he know?

Your third suggestion is also correct but then it's called as a declarative question where you are somewhat sure that he knows! I read it in Swan's Book, Practical English Usage.

Example -

She's your girlfriend?


Entirely a point of view, but I've noticed the choice of one of those statements can depend on the point of the sentence.

If there is some specific information at issue eg, some piece of news or gossip, then the first example will generally be used. "I'm telling Steve that Michelle has been seeing Peter." "OMG, does he not know?"

On the other hand, if the lack of intelligence is the point of the sentence in some form, then the second seems more common. "Michelle needed to use her calculator to find three multiplied by eight." "OMG doesn't she know her times tables?"

This aligns somewhat with the negation in the first being applied to 'knowing' and in the second to 'doing'. It's also not a hard and fast rule, just how I've seen it used.

PS: It's rather archaic, but you could throw a fourth form in there: Does he know not?

  • And you can add the Yodaic form: "Know not, does he?" It's very important for ESL learners to know about this form which is never taught in ESL classes for some reason. Commented Mar 27, 2014 at 21:49
  • Is not the form Yodaic: 'Know he, does not'?
    – mcalex
    Commented Mar 31, 2014 at 8:00

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