since
1.They left town and haven't been here since.
他们离开了镇子,从那以后再也没有来过这儿
2.They have been friends since childhood.
他们从幼时起一直是好朋友
3.She's been skiing since childhood.
她从幼时起就开始滑雪
4.My friend has since married and moved to California.
我的朋友从那以后就结了婚并移居到加利福尼亚
5.It is three years since we have been here.
我们在这儿呆了三年.
6.He has been skating since 9 o'clock.
他从9点钟就开始溜冰了.
7.He has studied very hard since he came to our school.自从他来到我们学校,他学习就非常努力.
8.We have been missing them since they left here自从他们离开这里,我们就一直很想念他们.
9.I haven’t heard from him since he has lived there.自从他（开始）住在那儿起,我就一直没收到他的来信.
10.It’s a long time since he studied English 他好久没学英语了.
for
1.My brother has had(不能用has bought) this bike for almost four years.
2.I have been in the army for more than 5 years.我在部队已经呆了五年多了.
3.He has lived in Beijing for 8 years .
4.The lazy boy has been lying in bed for a whole day.这个懒孩子在床上躺了一天了.
5.The film has been on for 15 minutes.
6.He has played the computer games for servral hours.
7.I have been diong my homework for 2 hours.
8.She has been crying for half an hour.
9.We have been here for a week.
