限制性定语从句不用逗号与主句分开，对所修饰的词起特指或限定的作用，去掉后意思不完整或不太清楚。翻译成中文时，一般把定语从句翻译在先行词之前。 eg. This is the man who helped me. 这就是帮助过我的那个男人。（如果缺乏了从句则主句意思不明确）I was the only person in our office that was invite to the palace ball. 我是我们办公室里唯一一个被邀请到宫殿厅的人。非限制性的定语从句和主句之间往往用逗号分开，只对被修饰的词语或主句起补充说明的作用，去掉后对句意影响不大。翻译时通常把定语从句翻译在先行词后边，作为附加说明。 eg. I have two sisters, who are both doctors. 我有两个姐妹，她们都是医生。（除去从句也可以表达清楚）Last Sunday they reached Shanghai, where a meeting was holding. 上个星期天他们到达了上海，那儿正有一个会议召开。
