一.在不同詞條里區(qū)別是不同的,但of通常指人的品質(zhì)或是名詞所有格中指無(wú)生命的部分；而for常譯為“為了”表示原因或者目的.
of:
prep.…的,表示所屬
例句與用法:
1.Many of the students came from other countries.
學(xué)生中許多人來(lái)自其他國(guó)家.
2.I have heard of him.
我聽(tīng)說(shuō)過(guò)他.
3.He is the best of teachers.
他是最好的老師.
4.I've never heard of such places.
我從未聽(tīng)說(shuō)過(guò)這些地方.
5.My phone was out of order.
我的電話壞了.
6.Joan of Arc was made a saint in 1920.
1920年,貞德被追封為圣女.
7.I'm under a lot of pressure.
我的壓力很大.
for:
conj.因?yàn)?br/>prep.給,為
例句與用法:
1.He shook his head,for he thought differently.
他搖搖頭,因?yàn)樗南敕ㄅc此不同.
2.Are you for or against?
你是贊成還是反對(duì)?
3.What can I do for you?
我能幫你什么忙嗎?
4.He has a great respect for his father.
他很敬佩他的父親.
5.It is for her own good.
這是為了對(duì)她自己有好處.
6.Jim is going to get material for a new book.
吉姆正打算為一部新書準(zhǔn)備材料.
7.They jumped for joy.
他們高興地跳了起來(lái).
8.We have studied English for years.
我們學(xué)英語(yǔ)已有好幾年了.
二.Is she your sister?回答是Yes,she is./No,she isn't.
三.Is it your pen?的回答,是Yes,it is./No,it isn't.
四.Is she your sister?和Is it your pen?問(wèn)的對(duì)象不同,所以回答當(dāng)然也不同,
Is she your sister?問(wèn)的是人,要用人來(lái)回答（she,he,we,I）
Is it your pen?問(wèn)的是物品（your pen）,要用物來(lái)回答（it,they）