改错题出现的错误经常包括：语法；词汇；语篇
1. 语法包括英语的时态，语态，倒装句，虚拟语气，主，谓，宾在数，格，人称上的一致。
2 .词汇方面，短文改错在用词上的错误主要集中在以下几个方面：
名次单复数，可数名词和不可数名词的差异，形容词与副词，连词与介词的误用，同义词的混淆等。
3. 语篇的改错旨在测试做题者在具体语境上下文中使用语法和词汇的能力。从逻辑的意义上看，句与句之间的关系可以分为顺序，并列，时间，空间，层递，对比，转折，解释，因果，过渡，推论等。最好的做法是先通读全文，结合上下文的逻辑关系回答问题。
 
The great whales are among the most fascinating creatures which __1__
have ever lived on the earth, and one of them, the blue whale, is the
largest. People in ancient times thought whales as fearsome __2__
monsters of the ocean depths. So to hunt a whale, when one
occasionally swam toward shore, he was high adventure. People __3__
found the adventure was rewarding, too, for the oil and meat from
one whale alone could heat and feed a village for a whole winter.
Whales resemble huge fish. They were referred by the ancients as __4__
“great fish,” and any whale beaching along the coasts of England
was designated “the King’s fish” because it automatically belonged
to the Crown.
Ever since those early times, human have felt whales a sense of __5__
wonder mixed with an intense desire to capture, slaughter, and
exploit. Now the slaughter has reached alarming proportions. __6__
Even though some species are protected by the regulations of
the International Whaling Commission and theoretically all whale
hunting is regulated, but the earth’s stock of whales is still being __7__
depleted. In fact, some scientists worry that 100 years since now __8__
there may be no whales left. If this happens, mankind will
be blame for removing from the earth forever a remarkable and __9__
awe-inspiring creature that always fed man’s imagination and __10__
made the world a more exciting place

 参考答案及解析:
1. 将which改为that。先行词由最高修饰时定语从句的关系代词只能用that。

2. 在thought 后面加of，或者将thought 改为regarded。“think of A as B”，指“把A看作B”，为固定搭配。

3. 去掉he。这句话的主语是“to hunt a whale”，“to hunt a whale was high adventure”。中间的“when…”只是插入的状语从句。

4. 在referred后加to。“refer to A as B”只“把A称作B”，这句话的意思是“古人把鲸称作大鱼”。

5. 在felt 后加for。这句话实际的结构是“feel a sense of wonder for whales”指“对鲸怀有惊奇的感觉”，for引出对象。

6. 在exploit后加them。capture，slaughter，exploit都是及物动词，后面必须加宾语。

7. 去掉but。前面已有“even though”，后面就不应该再用but。

8 .将since改为from。“100 years from now”指“从现在起100年后”since 只能用于完成时。

9. 在blame前加to。“be to blame for sth ”指“对某事应负责任”，为固定搭配。

10. 在always前加has。这个定语从句强调对现在的影响，很明显应该用完成时，不能用过去式。