did not you tell me vs didn't you tell me

Hi,

Why is it that we can say: 'why didn't you tell me' but can't say 'why did not you tell me' and have to invert the pronoun if the contracted form isn't used?

We can say 'why did not you tell me?', but we just don't say it. It's not idiomatic.

We can also say 'why did you not tell me?' We do sometimes say this if we want to stress the 'no

Why is it that we can say: 'why didn't you tell me' but can't say 'why did not you tell me' and have to invert the pronoun if the contracted form isn't used?

For the exact same reason we can say "They are", but can't say "They is". It's a rule of English.

No CJ. That's very different. We can't say 'they is' because it is ungrammatical in terms of number agreement. 'they' 3rd person plural. 'is' 3rd person singular. Whilst my question is completely unrelated to number agreement. Come on, CJ, you should that. Rudimentary stuff!

I think the first replier had the right idea: it is not ungrammatical just unidiomatic.

Any more takes..

It seems you knew the answer before you asked the question.

The point I was making has nothing to do with any specific rule. It has to do with the fact that it is a "rule".

"Rule" 14827739 (or whatever number you want to give it): Subjects and verbs agree in number.
"Rule" 40378299 (or whatever): In forming an interrogative, do not invert the negative not wi

CJ, You sound so smart! I love how you can explain grammatical rules so clearly.

great and clear answer!

I normally like your comments on this forum, but this is very wrong. There is no such rule, and "did you not" should sound very formal to someone from California, but it is definitely grammatical. I don't think you're thinking it through. British people (especially RP people) love this form, and in some other cases, it's unavoidable. As in, "How did you not know?"

If you said, "How