for 与 since 的紧张差异真的很大略，紧张记住一点，它们的差异就能迎刃而解，便是碰着韶光点用 since，比如详细的年月日或事宜等；韶光段用 for，不一定是一个详细的韶光段，但必须是一个韶光段，比如：几天、几周或几个月等等。
一、用 for 或 since 完成下面的句子
1 They have been living in Madrid _____ 1972.
2. He has been in prison _____ four years.
3. He has known about the fact _____ a long time.
4. Conditions have changed a lot _____ we were children.
5. Our teacher has been very ill _____ the last month.
6. I haven't eaten anything _____ twenty-four hours.
7. In fact he is always very rude. We have been waiting for him _____ half an hour.
8. I haven't seen him for three years. It is because I haven't been there _____ I left school.
9. I have been trying to mend this old fashioned car _____ hours.
10. One of my friends has been teaching in Tokyo _____ three years. I haven't met him since last year.
11. I haven't enjoyed myself _____ two weeks since I heard that my final exam grades were low.
12. I know that you have never seen a lion _____ you were born. Then now I say that we can go to the zoo and see one.
13. The police have been looking for him for two weeks _____ he escaped from the prison.
14. He hasn't spoken to me even a word _____ the last meeting.
15. I haven't phoned him _____ a week.
16. He has been the principal of our high school _____ 1988.
17. Dean has been learning Japanese _____ two years.
二、答案、参考翻译及解析
1. since
他们从1972年起就住在马德里。
解析：详细的年 1972 是韶光点，以是用 since.
2. for
他入狱四年了。
解析：四年是一个详细的韶光段，以是用 for.
3. for
他早就知道这个事实了。
解析：a long time 是一个不详细的韶光段，以是用 for.
4. since
自从我们还是孩子以来，情形发生了很大的变革。
解析：we were children 是详细的事宜（韶光点），以是用 since.
5. since
上个月以来，我们老师病得很厉害。
解析：the last month 是韶光点，以是用 since；在实际的运用中，可以用逆向的思维来作答，比如若不愿定是否能用 for，就试着用 for 去替代 since，你会创造意思完成行不通，或是你根本就不能翻译畅通。
把稳：有的时候是 last months，就要考虑用 for.
6. for
我已经24小时没吃东西了。
解析：twenty-four hours 是一个详细的韶光段，以是用 for.
7. for
事实上他总是很粗鲁。我们已经等了他半个小时了。
解析：half an hour 是一个详细的韶光段，以是用 for.
8. since
我已经三年没见他了。由于我离开学校后就没去过那里。
解析：I left school 是详细的事宜（韶光点），以是用 since.
9. for
我已经试着修这辆老式汽车好几个小时了。
解析：hours 译为“永劫光”，是一个不详细的韶光段，以是用 for.
10. for
我的一个朋友在东京教书三年了。从去年起我就没见过他。
解析：three years 是一个详细的韶光段，以是用 for.
11. for
自从听说我的期末考试成绩很低以来，我已经两个星期没玩得愉快了。
解析：two weeks 是一个韶光段，以是用 for.
12. since
我知道你从出生起就没见过狮子。现在我说我们可以去动物园看一个。
解析：you were born 是详细的事宜（韶光点），以是用 since.
13. since
自从他越狱以来，警方已经找了他两个星期了。
解析：he escaped from the prison 是详细的事宜（韶光点），以是用 since.
14. since
自早年次见面后，他一句话也没跟我说。
解析：the last meeting 是详细的事宜（韶光点），以是用 since.
15. for
我已经一个星期没给他打电话了。
解析：a week 是一个详细的韶光段，以是用 for.
16. since
他自1988年以来一贯是我们高中的校长。
解析：详细的年 1988 是韶光点，以是用 since.
17. for
迪恩学日语已经两年了。
解析：two years 是一个详细的韶光段，以是用 for.
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