1. We have been in this store for 20 minutes, and we haven't bought anything yet.
Здесь используешь Present Perfect Continious.
2. What is he doing? - He is playing tennis. - How long has he been playing tennis? - 2 hours.
Здесь используешь Present Perfect Continious и Present Continious.
3. They have been traveling for two weeks and have called two times (or twice for example).
Здесь используешь Present Perfect Continious.
4. Where is Molly? - She is ill. - How long has she been ill? - She is been ill since Thursday.
Здесь используешь Present Perfect Continious.
1. The chief engineer wasn’t in his office a few minutes ago.
Was the chief engineer in his office a few minutes ago?
2. I didn’t write a letter to Nick in the morning.
Did I write a letter to Nick in the morning?
3. I didn’t speak to the Dean on Tuesday.
Did I speak to the Dean on Tuesday?
4. They didn’t go to the country for the weekend.
Did They go to the country for the weekend?
5. This student didn’t take an active part in the discussion yesterday.
Did this student take an active part in the discussion yesterday?
Объяснение: