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Hi, I saw a question tag using "did he not?" in my grammar book, but I've never seen this structure before. Soon after that, I also thought of a similar structure:

I'm late, am I not?

While I know the above example is correct, I'm not sure if other question tags and questions could use this kind of structure as well. So I've made several sentences. Could you please see if the following sentences are acceptable? Thank you!

He used to smoke, did he not? (=didn't he?) (This one is what I saw in my grammar book)

He broke the window, did he not? (=didn't he?)

I can go, can I not? (=can't I?)

Your mother is a teacher, is she not? (=isn't she?)

All we want is peace, is it not? (=isn't it?)

Is it not almost 2 o'clock? (=Isn't it...)

Why did you not come to lunch with us? (=Why didn't you...)

Are you not having a good time? (=Aren't you...)

Did you see that girl in red dress? Is she not Mary? (=Isn't she...)
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With the tags, all of them are grammatical, and all of them will mark you as a non-native speaker, at least in the U.S. No one says it that way, except in cases where you really want to emphasize something: You DID remember to unplug the iron before we left, did you not??

(In other words, Lord help you if you didn't.)

With the straight questions, the non-contracted form is also used for emphasis, or to show that it's a sincere question, not a random "small talk" thing to say. "Oh dear. Are you not having a good time?" sounds like a real inquiry, not something said almost in passing.

However, the lesson here is for standard statements/questions, in which no particular emphasis is needed, use the versions with the contractions.
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Grammar GeekWith the tags, all of them are grammatical, and all of them will mark you as a non-native speaker, at least in the U.S. No one says it that way, except in cases where you really want to emphasize something:
A good example of something that is perfectly ok, but is not common and sounds quite weird in certain registers that are fundamental for ESL learners, which are informal registers. Emotion: smile
So, Viceidol, native speakers' speech is so full of reductions that, say, did he not? sounds strange compared to the usual did a knee? ...But of course it's not an impossible construction.
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Comments  
I agree with Grammar Geek here with one exception.

I think the last example "Is she not Mary" would raise eyebrows among native speakers no matter what the situation was.
 Kooyeen's reply was promoted to an answer.
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Viceidol,

The writer has to define the tone and emotion in which the tag question was asked. Whether it’s negative or positive tag, the first part of the tag forms the part which you believe or in denial to believe, the second part validates it. The most common tags are Positive with negative tag, and negative with possitive tag. But they can be negative with negative tag and postive- postive tag.

If you asked me to borrow $20,000 and I looked you in the eyes and say

“you are not serious, are you?”.

Let’s say I lent you the $20,000. Two weeks later you came to my house with a new car and asked me for 20,000 more. I said “you didn’t spend the 20 thousand I loaned you on this car; or did you?”.
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