在英语中按句型来说可以分为陈述句、疑问句、祈使句和感叹句四种，从结构上来说又可以分为简单句、并列句和复合句三种。句子的结构错误是构成句子完整结构的某一成分用错或者缺少，或者使用了多于成分而造成句意不清的错误类型。由于英语语法和汉语语法特点在结构上表现得十分明显，主、谓、宾结构在数、格、人称上的一致、连接手段的正确使用以及词序安排等，都与汉语有着相当大的差异，因此在改错中也是一大难点。句子结构错误类型包括：句子类型使用错误、句子成分短缺、平行结构错误以及词组搭配使用错误。
例 1
Computer analyzed marketing reports can help
deciding which products to emphasize now, which
to develop for the future, and which to be dropped. 1.__________
本句中三个平行成分 which products to emphasize now, which to develop for the future, and which to be dropped 结构模式应该一致，均采用不定式主动语态，因而 to be dropped 应改为 to drop 。
例 2
When we consider the comfortable circumstances
of a working family today, the life of the workingman
in 1882 seems miserable indeed. But earlier it had
been ever hard. 1.__________
根据上文中“ earlier ”可知，原句显然是将 1882 年以前的生活与 1882 年时的生活作比较，所以此处 hard 应该改为 harder 。
例 3
At the beginning of the nineteenth century working
hours were from sunrise to sunset, pay was awful,
and working conditions being poor and dangerous. 1.__________
在该句中， working hours were from sunrise to sunset, pay was awful, and working conditions being poor and dangerous 三个小分句为并列结构关系，因此必须保持成分和结构上的一致性，故应该将 being 改为 were 。
例 4
However, a second person thought that this was
more a question of civilized behavior as good 1.__________
manners.
“ more…than… ”是固定搭配用法，在此句中表示“与其…不如…”的意思，而不是“比…多”的意思；没有“ more…as… ”的搭配用法，故应该将 as 改为 than 。
练习题
1 On the contrary, the intimate atmosphere of the
small college allows the student four years of structural
living in which to expect and preparing for the real world. 1.__________
the student must, therefore, consider a great many factors.
Going to school is part of the socialization process,
and so going to the movies. 2.__________
3 The next morning the sun rose like a red ball on the
eastern horizon. But somehow after breakfast it hid
itself behind patches of clouds but it seemed a rain was 3.__________
apparent.
4 But luckily, no sooner had we entered the car when it 4.__________
suddenly began to rain.
5 That is worthy of note about these two groups is that 5.__________
among the 40 people there are only two women.
6 Women members are so less than members that we 6.__________
again think of the outdated prejudice that women are
inferior in intelligence.
7 The best way to avoid using dictionaries when you
are reading English books is to try to remember many 7.__________
words as you can.
8 It is just on that day when I bumped into Miss Helen 8.__________
on my way to work.
9 It is in the cinema not on the street where he lost his 9.__________
wallet which contained ＄
undersea, and special underwater ships will be designed
for mining, fishing, and to exploring unknown areas. 10.__________
答案解析：
1.preparing→prepare。属于平行结构中的动词错误。在并列连词and前后显然要有形式一致的动词，但前面没有与preparing呼应的现在分词（注：同行中的living是in which中which的先行词，故一定是名词，而不是现在分词——这是词形表面上的干扰），故只能改动preparing使之与前面的动词不定式expect一致，这里也有考生将preparing改为prepares，用意是与句中谓语动词allows一致，但要注意，句中不定式expect是及物动词，它的宾语是“the real world”，必须与prepare for共享。
2.so后面加is。该句是一个并列句，第一个分词结构是完整的，主语由动名词“going to school”担当，第二个分词表语部分与前面相同。为避免重复，而使用代词so，但是谓语不能省略，必须加上is才是完整的结构。
3.but→and。
4.when→than。“no sooner…than…”和“hardly…when…”是固顶结构，相互之间不能交换使用。
5.that→what。该句结构比较复杂，前面整个句子作为主语，但是that不能作为主语从句的主语成分，因此改成what。
6.less→fewer。
7.many前加as。
8.when→that。因为该句是一个强调句，所强调成分的代词除了在所强调成分为“人”时使用who或者that的情况外，一律使用that。
9.where→that。
10.删除to。
