(1)
1. I'm tired. I have been working all day.
2. She has been studying English for five years.
3. I have been travelling a lot since you last saw me.
4. We have been talking about it for a week.
5. Nobody has been opening the windows since last weekend.
(2)
1. Kate has known this girl since she was younger.
2. We have been here for 10 minutes.
3. They haven't seen each other since last month.
4. Mr Smith hasn't had enough money for many years.
5. We haven't been in New York since last holidays.
(3)
1. It has been raining since yesterday.
2. Tom's father has been building his house for two years.
3. Peter and Kate have known each other for ten years.
4. I ahven't gone out for three days. I have been ill since Saturday.
5. My friend has been working on the project for two weeks.
