由于定語從句的結構和用法比較復雜，初學者在使用時往往容易犯一些錯誤，最常見的有如下七種：

　(一)、在定語從句中加了多余的定語。如：　

1．誤：Some of the boys I invited them didn’t come．

　正：Some of the boys I invited didn’t come．

　譯：我邀請的男孩中有幾個沒有來。

　析：應刪去them，因為從句的賓語是省略了的whom，who或that。

(六)、定語從句與同位語從句

　定語從句相當于形容詞，它對先行詞起修飾、描述或限制作用，而同位語從句則相當于名詞，它對其前面的詞給予說明或作進一步解釋，即說明該詞所表示的具體內容。例如：

　The news that we heard is not true.(定語從句)

　The news that he won the prize is not true.(同位語從句)

　另：在"have no idea+從句"結構中，其從句都作idea的同位語。例如：

　I have no idea when she will be back.

(五)、定語從句中的先行詞

　Is this book the one that you bought yesterday?

　Is this the book that you bought yesterday?

　第一個句子中，this book是主句的主語，the one 是先行詞。在第二個句子中this是主句的主語，the book是先行詞。一定要避免出現(xiàn)：Is this book that you bought yesterday?

(四)、定語從句與狀語從句

　He found the books where he had put.

　He found the books in the place where he had put.

　第一個句子為狀語從句，where he had put 作主句He found the books 的地點狀語。第二個句子為定語從句，where引導從句修飾the place。

　This is such an interesting book that I'dlike to read it.

　This is such an interesting book as I'd like to read.

　第一個句子為結果狀語從句，在結果狀語從句中，it指代book,作read的賓語。第二個句子為定語從句，關系代詞as指代先行詞book的定語從句中read的賓語。

(三)、定語從句與并列結構

　He has two sons,neither of whom looks like him.

　He has two sons,and neither of them looks like him.

　I've got two sisters.Both of them are in Shanghai.

　第一個句子為定語從句，關系代詞whom指代two sons,在定語從名中介詞of的賓語。第二個句子為并列結構，由并列連詞and連接，人稱代詞them指代two sons。第三個為兩個獨立的句子，兩個句子中間用句號，兩句開頭的處一個字母都大寫。

(二)、定語從句與強調結構

　It is the place where they lived before.

　It is in the place that they lived before.

　第一個句子為定語從句，where指代the place,在定語從句中作狀語，第二個句子為強調結構，強調in the place,that沒有意義，把in the place 放回后面句子，句子意思完整。

　Where is it that he found the lost watch?(強調句型，強調疑問副詞where)。

　Where is the watch that he found yesterday.(定語從句，that指代the watch)

　 定語從句又稱為關系從句，是最常見的從句之一，每年高考題對之均有考查。

(一)、定語從句中關系代詞與先行詞的一致性

　定語從句中關系代詞一般應與它所指代的先行詞的單復數(shù)保持主謂一致。例如：

　The students who were here just now are from No,2 Senior Middle School.

　但注意下列一組句子：

　He is the only one of the students who was here just now.

　He is one of the students who were here just now.

　如果"one of +復數(shù)名詞"后跟有定語從句，一般情況下"one of"后的復數(shù)名詞為先行詞，但當one前有the only,the very,just the修飾時，先行詞則為one。

2．As引導的非限制性定語從句的位置

　as引導的非限制性定語從句位置較靈活，可以位于主句前面．中間或后面，一般用逗號與主句隔開，但which所引導的非限制性定語從句只能放在主句之后。例如：

　(1) As is expected, the England team won the football match.

　(2) The earth runs around the sun, as is known by everyone.

1. 引導限制性定語從句和非限制性定語從句

　 (1)as多與such 或the same連用，可以代替先行詞是人或物的名詞。

　 (2)as 也可單獨使用，引導非限制性定語從句，作用相當于which。例如：

The elephant’s nose is like a snake, as anybody can see.

　 (3)the same… that與 the same …as在意思上是不同的。

3.　先行詞與定語從句隔離

　定語從句一般緊跟在先行詞之后，但定語從句與先行詞之間有時也會插入別的成分，構成先行詞與定語從句的隔離。例如：

　1) This is the article written by him that Is poke to you about..

　2) He was the only person in this country who was invited