[误] After school some students play football, or others go to the library.
[正] After school some students play football, while others go to the library.
[误] She sang when she walked along the dark street.
[正] She sang as she walked along the dark street.
[误] I finished my homework until twelve o'clock last night.
[正] I didn't finished my homework until twelve o'clock last night.
[正] I did my homework until twelve o'clock last night.
[析] until用在句中时其含义是某一动作一直持续到某时结束，那么句中的动词则一定要用持续性动词，如果要用瞬间，或截止性动词时一定要用否定句式。因截止 性动作的否定式应看作是持续性的动作。如离开leave是瞬间动作，因一出门即为离开了，而不离开则是长时间的。
[误] I have studied English when I was twelve.
[正] I have studied English since I was twelve.
[误] Because he didn't study hard, so he didn't pass the exam.
[正] He didn't pass the exam because he didn't study hard.
[析] because 与 so在英文中两者不能并用的，只能在句中用其一。
[误] He was such excited that he could not speak.
[正] He was so excited that he could not speak.
[析] so与such的用法可以分为四种情况，①用于单数可数名词之前，其格式是such+不定冠词+形容词+单数可数名词，如：It is such a beautiful book that every child likes it. 也可以用so, 其格式是so+形容词+不定冠词+单数可数名词，如：It was so beautiful a book that every child likes it. ②在不可数名词前或可数名词复数前这时只能用such, 如：It is such good weather that we want to swim. 又如：They are such good students that they can pass the exam easily. ③在few, little， much, many 这4个字前只能用so而不能用such, 如：I have so much money that I can buy everything I want. ④当that前只有形容词或副词时，这时只能用so, 如：She is so beautiful that every one likes her. He ran so fast that I couldn't keep up with him.
[误] He got up earlier this morning so as to that he could catch the first bus.
[正] He got up earlier this morning so as to catch the first bus.
[正] He got up so earlier that he could catch the first bus.
[析] so…that与so that的用法有相同之处，那就是其后接从句，而so as to 其后要接不定式，即动词原形。这样的词组还有：in order to。
[误] I want to buy same stamp that you have.
[正] I want to buy the same stamp as you have.
[析] the same…as (that)这是个固定用法，在same前的定冠词是不能少的。而the same…that意为"我要的就是那一个"。而the same…as为"要的是和……一样的东西"。
[误] Before I do not give you the answer, I'll ask you some questions.
[正] Before I give you the answer, I'll ask you some questions.
1? We bought Granny a present, ___ she didn't like it.?
A. but B. and
C. or D. so
2? Run quickly, ___ we'll miss the early train.?
A. and B. but
C. so D. or
3? I'll give the book to him ___ he comes back.?
A. since B. as soon as
C. before D. until
[析] as soon as 引出的时间状语从句应用一般现在时表示将来要发生的动作。
4? Don't cross the road ___ the light turns green.?
A. when B. while
C. until D. as
[析] until应译为"直到……才"，因为前面的祈使句为否定句。又如：She did not go to bed until her mother came back. 应译为"直到她妈妈回来她才睡觉"。
5? Miss Gao has been a teacher ___ 1990.?
A. before B. after
C. since D. in
[析] 因为主句为完成时，所以应用 since表示该动作的启始点。
6? - Which would you like better, tea ___ milk??
- Tea, please.?
A. but B. and
C. or D. with
7? We love spring ___ there's beautiful flowers every wher.?
A. though B. but
C. or D. because
8? Please leave ___ 7∶00, then you'll be able to get ___ there earlier.?
A. till, in B. from, /
C. before, / D. behind, to
9? The teacher didn't begin the lesson ___ all the students stopped talking.?
A. until B. after
C. if D. because
10? Betty didn't go to see the film yesterday ___ she was ill.?
A. but B. until
C. if D. because