правило займеник?помоготе написать

Очень скорчно нужно:Помогите пожалуста раскрыть скобки и определить время:
Ann and Nick often...(help) each other to do their h/w.
We...(to write) a test yesterday.We...(to write) a test  for the whole lesson yesterday.We...(to  write) a test by the end of the lesson.
Kate ...(not to like) her new teather.She ...(to be) very strict.The woman ...already ...(to buy) everything for dinner in the shop.
What ...Helen ...(to do) at 2 p.m. yesterday?
Спасибо большое заранее...