Как поставить вопрос к этим предложениям в форме past simple they

They started work at nine oclock this morning. - Did they start work at nine oclock this morning? When did they start work?
The pupils understood that very well. - Did the pupils understand that very well?
His brother went to Kiev every year. - Did his brother go to Kiev every year? Where did his brother go every year?
My aunt grew beautiful roses. - Did your aunt grow beautiful roses? What did your aunt grow?

Вопросительная форма Past Simple образуются с помощью вспомогательного глагола did (который ставиться перед подлежащим) и смыслового глагола в форме инфинитива без to.