Как образует вопросы и отрицательные предложения конструкция “used to do something”?...

Question

Как образует вопросы и отрицательные предложения конструкция “used to do something”? Приведи пример

Answer 1

I used to do exercise in the morning.
I didn't use to do exercise in the morning.
Did he use to do exercise in the morning?

Answer 2

Did he use to smoke when he was young?

He did not use to smoke when he was young.