英语句型包含的内容是很丰富的。从大的方面看，如按结构分，可分为简单句、并列句、复合句和并列复合句；从某一方面的用法看，可以有强调句型、倒装句型等；从具体某个结构来看，还有 so…that…, such…that…, not…until…, too…to… 等众多的句型。这些不同的句型，各有各的特点，同学们在学习时须引起注意。下面举几个例子来说明：
◇下面有三个试题，你能准确地选出最佳答案吗？
(1) He wrote a lot of books, and most of _________ were popular.
A. them B. whom D. that D. which
(2) He wrote a lot of books, most of _________were popular.
A. them B. whom D. that D. which
(3) He wrote a lot of books, most of them _________ popular.
A. was B. were D. being D. to be
有的同学认为第(1)题选D，第(2)题选A，第(3)题选B，你同意吗？如果你同意，那你就全错了，想知道这是为什么吗？
◇许多同学都知道，汉语中类似“因为下雨，所以我没去”，“虽然我很累了，但我仍继续工作”这类句子，不能直译为 Because it was raining, so I didn’t go. Thought I was tired, but I went on working. 为什么呢？有的同学总结为：英语中的 because 不能与 so 连用，thought / although 不能与 but 连用。当然这样归纳也还实用，且有助于记忆。但是，你知道它们为什么不能连用吗？换句话说，你知道其中的 why 吗？下面两个句子中就将 though 与 but 用在一起了，它们错了吗？
But I didn’t know that then, although I learned it later.
I tried doing the accounts, but although I knew some maths I found it very difficult.
想知道以上问题的详细解释吗？快往下看。
1. He wrote a lot of novels, most of _________ were popular.
A. them B. whom D. that D. which
【分析】此题最佳答案为D，但很容易误选A。假若单独看 He wrote a lot of novels 和 Most of them were popular 这两句话，它们并不错，但将它们放在一起用逗号连接就不甚妥当了。因为，英语句子按其结构来划分，可分为简单句、并列句、复合句和并列复合句四种，也就是说，一个规范的英语句子，从结构上说，它必须隶属以上四类句型之一。但上面一题若选A，则它既不是简单句(因为它有两个主谓结构)，也不是并列句(因为它没有并列连词)，也不是复合句(因为它没有主从句之分)，当然它更不是并列复合句，所以选A是错误的。可以选D，是因为空白处填了 which 之后，后一句即成了一个非限制性的定语从句，前一句即为主句，整个句子即为一个复合句。比较以下各句(www.yygrammar.com)：
(1) He wrote a lot of books, and most of them were popular.
句中用了并列连词，整个句子为并列句。
(2) He wrote a lot of books, most of which were popular.
后一句用了 which，使之成为定语从句，整个句子为复合句。
(3) He wrote a lot of books, most of them being popular.
后一句用了非谓语动词 being，故逗号处不用并列连词，整个句子为简单句。
2. Just because they make more money than I do, _________ they seem to look down on me.
A. so B. and C. but D. 不填
【分析】此题正确答案为D，但容易误选A，将汉语的“因为……所以……”直译为 because … so …，但是按英语语法，because 为从属连词，用以引导原因状语从句，它表明整个句子为复合句；而 so 在表示“所以”时，它是并列连词，用以连接两个简单句使之成为并列句。由于在同一句中既用了从属连词 because，又用了并列连词 so，使得该句一半像复合句，一半像并列句，从而导致错误。正确的做法是，任意去掉 because 和 so 中的一个，使之要么成为复合句，要么成为并列句。
3. Although he had only entered the contest for fun, _________ he won first prize.
A. but B. and C. even D. 不填
【分析】此题容易误选A，将汉语的“虽然……但是……”直译为 although … but …，但是按英语语法，although 为从属连词，用以引导让步状语从句，它表明整个句子为复合句；而 but 在表示“但是”时，它是并列连词，用以连接两个简单句使之成为并列句。由于在同一句中既用了从属连词 although，又用了并列连词 but ，使得该句一半像复合句，一半像并列句，从而导致错误。正确的做法是，任意去掉 although 和 but 中的一个，使之要么成为复合句，要么成为并列句。其实，此题与上面一题的分析思路是一样的。这里顺便说一句，许多同学(包括
But I didn’t know that then, although I learned it later. 但我当时的确不知道此事，尽管后来我还是知道了。
此句既用了并列连词 but，又用了从属连词 although，但它并未造成错误，原因是此句与上面所讨论的情形有所不同，即此句 but 用于 although 之前，but 在此仅起到与上文转折的作用，but 后的 I didn’t know that then, although I learned it later. 仍为一个复合句。
I tried doing the accounts, but although I knew some maths I found it very difficult. 我试着算这些账，但尽管我懂点数学，仍感到很困难。
此句将 but 与 although 用在一起，但此句也没有错误。该句从总体来看，它是一个以并列连词 but 连接的并列句，而在该并列句的后面一句又是一个包含让步状语从句 although I knew some maths 的复合句――这种句型就是所谓的并列复合句。此句也可改写为 I tried doing the accounts, but I found it very difficult although I knew some maths.
4. If they don’t understand it the first time, _________ over it again until they do.
A. going B. to go C. gone D. go
【分析】此题正确答案选D，其余几项均有可能被误选。空格前 if 引导的是一个条件状语从句，而在空格处无论是填A、B或C，它都是一个非谓语动词短语，而不是一个句子，这样一来，整个句子没有主句，从而导致结构不完整。若选D，则 go over it again until they do 则是一个句子(祈使句)，在此用作主语。又如：
(1) If he likes to eat it, _________ him some more.
A. give B. giving C. given D. to give
(2) If anyone calls, _________ them I’m not at home.(www.yygrammar.com)
A. tell B. telling C. told D. to tell
(3) When your mother comes back, _________ her to come to school at once.
A. ask B. asking C. asked D. to ask
(4) While the baby is sleeping, _________ your work as soon as possible.
A. finish B. finishing C. finished D. to finish
答案均选A，空格前分别为 if, when, while 引导的状语从句，空格处填动词原形，构成祈使句，用作句子主语。
5. If I’m mistaken, _________ you are mistaken too.
A. so B. and C. or D. 不填
空格前 if 引导的是一个条件状语从句，它暗示整个句子为复合句；而so, and, or 为并列连词，无论选哪一个，都表明整个句子为并列句，从而导致前后矛盾，所以A、B、C均不能选择。此题正确答案选D，you are mistaken too 为主句。又如：
(1) If wishes were horses, _________ beggars would ride.
A. and B. so C. or D. 不填
(2) When the last prize had been awarded _________ everybody cleared off.
A. and B. so C. or D. 不填
(3) Just before I left
A. and B. so C. or D. 不填
(4) After they had each said a few words, _________ Lloyd George took the floor.
A. and B. so C. or D. 不填
答案均选D，空格前分别为 if, when, before, after 引导的状语从句，空格后为句子主句。
6. Finding her car stolen, _________.
A. a policeman was asked to help
B. the area was searched thoroughly
C. it was looked for everywhere
D. she hurried to a policeman for help
【分析】此题最佳答案选D，因为句首用作状语的现在分词短语finding her car stolen 的逻辑主语应是“她”，而不是 a policeman, the area, it 等，按照英语语法，在通常情况下，非谓语动词用作状语时，它的逻辑主语应与句子主语保持一致，所以最佳答案为D。请再看类例：
(1) To master a foreign language, _________.
A. the school needs a foreign teacher
B. a good teacher is needed
C. a lot of practice is needed
D. one must have a lot of practice
【分析】此题答案选D，因为 to master a foreign language 的逻辑主语应是 one，而不是其他。
(2) _________ many times, he still didn’t understand it.
A. Having been told B. Though to be told
C. Having told D. He was told
【分析】此题答案选A，因为根据句意，he 与 tell 应是被动关系；另外，从时间上看，应该是“被告诉”在先，“没有理解”在后，故要用 having been told 这一现在分词的完成被动式。注意不能选D，因为 He was told 与 he still didn’t understand it 这两个简单句之间缺乏必要的衔接关系(参见下一题)。
(3) _________ many times, but he still didn’t understand it.
A. Having been told B. Though he was told
C. To have been told D. He was told
【分析】此题答案选D，句中的并列连词 but 表明整个句子为并列句，同时表明 but 前应是一个独立的句子，而不能是一个非谓语动词短语(所以不能选A或C)，又因为 though 为从属连词，用以引导让步状语从句，它与连接并列句的并列连词 but 不“兼容”，所以也不能选B。
7. He looked _________ funny that we couldn’t help laughing.
A. very B. much D. rather D. so
答案选D，请注意其后的 that，该句使用的是 so … that …句式，句意为“他看上去很滑稽，我们都禁不住笑了”。从语法角度讲，英语中的“very＋形容词或副词”结构通常不能用来引出结果状语，所以 so ... that-clause (如此……以致于)、so ... as to do sth (如此……以至于做某事)、too ... to do sth (太……以致于不能做某事)、enough to do sth (足够的……可以做某事)等结构中的 so, too, enough 等词均不能用副词 very 来代替。比较：
他气得连话都说不出话。.
正：He was so angry as to be unable to speak.
正：He was so angry that he couldn't speak.
正：He was too angry to speak.
误：He was very angry as to be unable to speak.
误：He was very angry that he couldn't speak.
误：He was very angry to speak.
再请做下面一题(www.yygrammar.com)：
18. Marsha got so carried away when arguing with her husband _________ she hit him.
A. since B. and C. until D. that
答案选D，属 so…that… 句式。全句意为“玛莎与她丈夫争吵过于激烈，以致动手打了他”。其中的 carry away 意为“使兴奋”、“使忘其所以”，通常用于被动语态，句中的 got carried away 可视为系表结构。