同学你好，该知识点来自沪江网校《初级起点直达PETS三级【随到随学班】》的课程，想要更系统的学习，欢迎进入课程学习。不仅可以和更多的同学一起学习，而且还有老师、助教随时的学习指导和知识点解答哦。

同学你好~

定语从句是对某个先行词进行修饰，说明先行词性质、状态的。
Mary likes music that is quiet and gentle. 玛丽喜欢轻柔的音乐。
The girl who often helps me with my English is from England.经常在英语方面帮助我的那个女孩是英国人。

同位语从句一般用that, whether，what,  who, when, where, why, how 等词引导，常放在fact, news, idea, truth, hope, problem, information, wish,promise, answer, evidence, report, explanation, suggestion, conclusion等抽象名词后面，说明该名词的具体内容。换言之，同位语从句和所修饰的名词在内容上为同一关系，对其内容作进一步说明。

也就是说，同位语从句是对idea, fact等单词的内容再说一遍，再重复一遍，内容上是一致的，是“同位”的。

The news that they had won the game soon spread over the whole school.
他们比赛获胜的消息很快传遍了整个学校。
析：they had won the game说明The news的全部内容，因此该句为同位语从句。
例：The general gave the order that the soldiers should cross the river at once.
将军下达了战士们立即过河的命令。
析：the soldiers should cross the river at once是the order的全部内容。

祝同学学习进步~