پرسش مربوط به استفاده از "for" و "since" در زبان یازدهم است. در اینجا پاسخها به این صورت خواهد بود:
1. My sister has been sick **for** a long time. She has been in the hospital **since** January.
2. Nobody lives in those houses. They have been empty **for** many years.
3. I have been interested in computer technology **for** four years.
4. My father is in his office. He has been there **since** 8 o’clock.
5. He has stopped smoking **since** the birth of his baby.
6. My parents have been married **for** 20 years.
7. We have lived in Shiraz **since** ten years ago.
8. We have known each other **for** 15 years.
9. I've painted two rooms **since** lunchtime.
10. He has been in China **for** two weeks.
این پاسخها بر اساس قواعد استفاده از "for" برای مدت زمان و "since" برای شروع زمانی است.
