学习者往往以为定语从句是对前面的名词有限定作用，那么则是特指了，先行词如有寇词则一定是the了，其实不然。

30. A sailor is a man that works in a ship。

31. He is the man that helped me yesterday。

要知道，有的定语从句只是对前面的名词作说明或解释。句30的定语从句是对行词作说明，说水手是一种。。。人，那是泛指的，不用the。而句31的定语从句是才特指的。

32 Is this factory_______ you visited last year?

a. the one c. that c. which d. where

33. Is this the factory_______ you visited last year?

a. the one c. that c. who d. where

十一。独立句与定语从句分不清

34. I met twenty students, some of whom are good at maths.

35. I met twenty students. Some of them are good at maths.

36. We reached the mountain, on the of which we saw a beautiful scene

37. We reached the mountain. On the of it (or: On its top ) we saw a beautiful scene

34 和36是主句和定语从句关系，所以我们要用关系代词，而在35，37各两句中，它们是各自的独立句子，所以用代词。当然在36中将on the top of which改为on whose top,则定语从句的关系 更为明显。

十二。分不清同位语还是定语从句

38. We heard the news that pleased everyone.

39. We heard the news that our term had won.

在这里要认清楚定语从句的关系词在从句中起句子成份作用，而同位语的that 不充当句子成份，句38中的that就充当了从句中的主语，在句39中that却不在从句中充当任何成份。再者同位语从句引导词还可以由其他的词来引导。如：

40. I have no idea what he going to do.

41. I have no idea whether he will come.

42. I have no ides where he will go.

十三。关于复合关系代词whoever, whatever等等

43.Whoever get the job will have a lot of work to do.

44. Whoever gets the job, he will have a lot of work to do.

45. Whatever she says goes.

46. Whatever she says, it goes.

在句43中whoever=anyone that 即有定语从句的意味，在句45中whatever=anything that也有定语从句的意味。而在44和46句中的whoever和whatever则是引导状语从句，所以它们后面的句子都有主语。

十四。定语从句与what引导的名词性从句的转换

47. He’s not the man that he was.

48. He’s not what he was.

49. China is no longer the country that it was.

51. China is no longer what it was.

我们常用名词+that改变成what的形式，如47，48句，它们的意义基本上是一样的，只不过用名词+that更为清晰。49，50句也是如此。