陷阱4 用错介词后动词的形式
按英语习惯，介词后接动词作宾语时，动词通常要用动名词，不用不定式或动词原形。如：
He makes a living by teaching. 他以教书为生。
She is quick at learning languages. 她学语言学得很快。
In crossing the street he was run over. 他在穿过马路时被汽车撞倒。
当表示“除……外”的介词but和except后接动词时，要用不定式(有时带to，有时不带to)。如：
Nothing remains but to die. 除了死没有别的办法。
He will do anything except cook. 他什么都愿做，就是不愿做饭。
It had no effect except to make him angry. 这除了使他生气没有别的作用。
陷阱5 忽略介词的有关搭配
介词是英语中搭配能力很强的一类词，其中有些搭配非常有用，而且也常常是中考英语的考点，如“with+宾语+宾语补足语”结构就非常值得注意。如：
He often sleeps with the windows open. 他常开着窗睡觉。
He stood before his teacher with his head down. 他低着头站在老师面前。
She said good-bye with tears in her eyes. 她含着眼泪说了声再见。
He fell asleep with the lamp burning. 他没熄灯就睡着了。
All the afternoon he worked with the door locked. 整个下午他都锁着门在房里工作。
I can’t go out with all these dishes to wash. 有这么多盘子要洗，我不能出去。
又如：by doing sth（通过做某事）也是一个很有用的表达。如：
He makes a living by teaching. 他以教书为生。
He began by telling us a story. 他先给我讲了个故事。
Lock this door by turning the key twice to the left. 锁这扇门要把钥匙向左转两圈。