41。误〕 Three days after he died。正〕 After three days he died。 〔正〕 Three days later he died。
〔析〕 after与later都可以用来表达一段时间之后，但它们所处的位置不同，after在时间词前，而later在时间词后。
42。〔误〕 She hid herself after the tree。 〔正〕 She hid herself behind the tree。
〔析〕 after多用来表达某动作之后，所以有的语法书中称它为动态介词，如：I run after him。 After finishing my homework， I went to see a film。而behind则多用于静态事物之后。
43。〔误〕 There is a beautiful bird on the tree。正〕 There is a beautiful bird in the tree。
〔析〕树上长出的果实，树叶要用on，而其他外来的人、物体均要用in the tree。
44。〔误〕 Shanghai is on the east of China。 〔正〕 Shanghai is in the east of China。
〔析〕在表达地理位置时有3个介词：in， on， to。 in表示在某范围之内; on表示与某地区接壤;to则表示不相接。如：Japan is to the east of China。
45。〔误〕 I arrived at New York on July 2nd。 〔正〕 I arrived in New York on July 2nd。
〔析〕 at用来表达较小的地方，而in用来表达较大的地方。at常用于at the school gate， at home， at a bus stop， at the station， at the cinema， at a small village。
46。〔误〕 He lived in No。 3 Beijing Road。 〔正〕 He lived at No。 3 Beijing Road。
〔析〕在门牌号码前要用at，并要注意它的惯用法：at the end of the street， at the foot of the mountain， at the top of the page。
47。〔误〕 There is a colour TV set at the corner of the hall。 〔正〕 There is a colour TV set in the corner of the hall。
〔析〕在屋内的角落应用in，而墙的外角用at，如：There is a tree at the corner of the street。
48。 〔误〕 Do you know there is some good news on todays newspaper? 〔正〕 Do you know there is some good news in todays newspaper? 〔析〕在报纸上的新闻要用in，而在具体某一版上，或某一页上则要用on。
49。 〔误〕 The school will begin on September 1st。 〔正〕 School will begin on September 1st。
〔析〕这里的school应看作不可数名词泛指学校的课程，即开学之意。要注意，有些活动场所当表达正在从事该种活动时不要加冠词，如：at table (吃饭)， When I came to Toms home， they were at table。还有： at desk (学习)，at work (工作) at school (上学)， in hospital (住医院) at church作礼拜如加上定冠词则另有他意，如：at the school即在学校工作或办事，in the hospital即在医院工作或去看望病人。
50。 〔误〕 Ill leave Beijing to Shanghai tomorrow。 〔正〕 Ill leave Beijing for Shanghai。 〔正〕 Ill leave for Shanghai。
〔析〕 leave for是离开某地去某处的固定搭配，不可将for改为别的介词。这样的搭配还有：start for动身前往某处，set out for， sail for。