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).
4. Where is Molly? - She is ill. - How long has she been ill? - She is been ill since Thursday.
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.