Which sentence is grammatically correct and why?
- I have been studying for my exam since lunchtime and now I am watching TV.
- I had been studying for my exam since lunchtime and now I am watching TV.
- I was studying for my exam since lunchtime and now I am watching TV
The situation is as follows:
- Is that the TV I can hear?
- Yes, Dad. I (to study) for my exam since lunchtime, and now I am watching TV.
Thank you in advance.