1. 介詞后的動詞用不定式還是動名詞
動詞用作介詞賓語時，動詞習慣上要用動名詞。如：
According to the air traffic rules, you should switch off your mobile phone before boarding. 根據航空運輸法規，登機前你應該關閉手機。
However hard you try, it is difficult to lose weight without cutting down the amount you eat. 不管你怎么努力去嘗試，不減少你的進食而去瘦身都是很困難的。
但是，有兩個詞是例外，即表示“除……外”的介詞 except和but 后通常接不定式作賓語，且這個不定式有時帶to(若其前沒有動詞do)，有時不帶 to(若其前有動詞do)。如：
If he takes on this work, he will have no choice but to meet an even greater challenge. 如果他接受這個工作，他將別無選擇，只能去迎接一個更大的挑戰。
2. 關于介詞后從句作賓語
用于介詞后作賓語的從句，可以由what, who, which, when, where, how, why等，但通常不能是that 從句，遇此情況應在介詞后加上 the fact。如：
Kelly loved her husband in spite of the fact that he drank too much. 盡管丈夫喝酒很兇，但凱莉還是愛著他。
Doris’ success lies in the fact that she is co-operative and eager to learn from others. 多麗絲的成功在于她的團結合作以及她積極向別人學習。
If it were not for the fact that she can’t sing, I would invite her to the party. 要不是因為她不會唱歌，我就會邀請她來參加晚會了。
3. 關于介詞短語用作介詞賓語
英語中有少數介詞可接介詞短語作賓語，這類介詞常見的有from, until, except等。如：
I hope the rain holds off until after the picnic. 我希望野餐結束前不要下雨。
The window is never opened except in summer. 除夏天外，這扇窗戶從未打開。
The next thing he saw was smoke rising from behind the house. 隨后，他看見的是，煙正從屋子后面升起。
4. to do還是to doing
to有時是不定式符號，有時是介詞，所以英語有時用to do，有時用to doing。對于許多同學來說，to do容易理解，但 to doing 則很容易搞錯。從中學英語所接觸的知識來看，to doing的用法主要僅于某些固定搭配，如：
adapt to doing sth 適應做某事
admit to doing sth 承認做了某事
apply to doing sth適用于做某事
object to doing sth 反對做某事
see to doing sth 負責做某事
stick to doing sth 堅持做某事
take to doing sth 喜歡上做某事
apply oneself to doing sth 專心于做某事
devote…to doing sth把……獻給做某事
be opposed to doing sth 反對做某事
reduce sb to doing sth 使某人淪為做某事
key to doing sth 做某事的關鍵
limit to doing sth 做某事的限度
pay attention to doing sth 注意做某事
set one’s mind to doing sth 決心做某事
be used to doing sth 習慣于做某事
get down to doing sth開始做某事
look forward to doing sth 盼望做某事
in addition to doing sth 除做某事之外
The key to solving the problem is to meet the demand made by the customers. 解決這個問題的關鍵就是滿足顧客的要求。
Be sure to pay attention to protecting the environment and be considerate while traveling. 外出旅游時務必注意保護環境，為他人著想。
We are looking forward to taking part in the opening ceremony of the art to be held next week. 我們盼望能參加下星期舉行的藝術節開幕式。
