改错
1.Is this the book your father bought it for you?
2.Who is the comrade you talked with him?
3.Have you been to the place where she works there ?
4.They are talking about the people and the things which they saw on their way home.
5.This is the very thing which I can tell you.
6.Is this all what you Wahl to say?
7.Shanghai is the biggest cit y，that has a population of more than ten million.
8.Which is the clock which is made in China?
9.Who is the man who is speaking to your mother?
10.I shall never forget the days when I spent with you
11.He has written a book.the name of it I have forgotten.
12.Father came back on April 4th when was my birthday.
13.Is this factory which you set up yourselves?
14.Is this the city where you visited last year?
15.This is the necklace for which she is looking.
参考答案：
1.去掉it。因为被省去的关系代词是从句中谓语动词的宾语。
2.去掉him。
3.去掉there，因为关系副词是从句中的状语。
4.改which为that。
5.改which为that，先行词被only，very，a11，much，little，few，nobody，no one，anybody，some-body，everything，nothing，anything以及形容词最高级、序数词所修饰时，关系代词用that。
6.改what为that。
7.改that为which，在非限制性定语从句中，修饰物用which。
8.改第二个which为that，以免重复。
9.改后面的who为that，以免重复。
10.改when为which或that，用作spent的宾语。
11.改the name of it为the name of which。
12.改when为which，作从句的主语。
13.改which为the one。
14.改where为which或that，作visit的宾语。
15.1ook for是短语动词，不能拆开使用。