I have a question regarding the question-tag. I hear that the negative question-tag can be made out of the following construction: helping verb + subject + not?
I have a meeting every day, don't I/do I not?
You should see me today, shouldn't you/should you not?
I am a great teacher, aren't I/am I not?
They had better do it, hadn't they/had they not?
They used to be kind, usedn't they/used they not?
Are all the ones in bold type grammatical?