What? What were you doing?
When? When were you doing this?
Where? Where are you doing this?
How? How are you doing this?
Why? Why are you doing this?
Whom? Whom are you doing this with?
Who? Who is doing this?
How long have you been doing this?
В этих вопросах вспомогательное слово (в зависимости от времени do, are/is, were/was, have/has, did, have been/has been, will (shall как вышtlitt из употребления) ) ставятся после вопросительного слова, за ними следуют глаголы в соответсвующем времени)