1) 当先行词带有表示类别的不定冠词时,其后的关系分句通常为限制性定语从句,例如:
She was a woman who must be treated decently.(限制性）
He spoke to me in a tone which I don't at all like.（限制性）
2）当先行词带有前照应定冠词时，其后的关系分句通常也为限制性的，例如：
He is the man who told me the news.(限制性）
This is the car I bought last year.(限制性）
3）当先行词带有all,any,some,every,no等不定限定词时，其后的关系分句也通常是限制性的，例如：
The first flame from Rainbarrow sprang into the sky ,attracting all eyes that had been fixed on the distant conflagration. (限制性）
Any man who smokes cigarettes is, the doctors say, risking his health.(限制性）
4） 当先行词是专有名词或物主代词和指示代词所修饰时，其后的定语从句通常是非限制性的，例如：
Charles Smith, who was my former teacher, retired last year.
查理·史密斯去年退休了，他曾经是我的老师。（非限制性）
This novel, which I have read three times, is very touching.
这本小说很动人，我已经读了三遍。（非限制性）
<二>限制性定语从句与非限制性定语从句的区别
1)含义不同(具体见篇首)
2)先行词不同。限制性定语从句的先行词只能是名词或代词；非限制性定语从句的先行词可以是名词、代词、短语或句子，另外当先行词是专有名词或其他具有独一无二性的普通名词时通常要用非限制性定语从句，例如：
Peter drove too fast, which was dangerous. 彼得开车很快，这是很危险的。(which指drive too fast)
He changed his mind, which made me very angry. 他改变了主意，这使我很生气。(which指整个主句)
Mr. Smith, who is our boss, will leave for Japan next week. 我们的老板史密斯先生下周要去日本。(先行词为专有名词，要用非限制性定语从句修饰)
Her father, who has a lot of money, wishes her to study abroad. 她父亲很有钱，希望她出国学习。(先行词为表独一无二意义的普通名词，要用非限制性定语从句修饰)
