同位语从句引导词图表
同位语从句会不会用逗号隔开？
同位语从句会不会用逗号隔开？
同位语一般置于本位语之后，可以不用标点符号隔开，也可以用逗号、冒号或破折号隔开，
例如：The thought came to him that maybe the enemy had fled the city.
这里thought就和它的由that引导的同位语从句被谓语部分came to him所分割。
同位语从句。
一个名词或代词后面有时可跟一个分句，对前者做进一步解释，说明它指的是谁或是什么等，这叫同位语。名词做同位语的情况最多，当然也有较复杂的结构。
例如：
We communists seek not official posts，but revolution.
The lay out plan was completed within three months，half the usual time.
Wei Fang，normally a timid girl，argued heatedly with them about it.
同位语从句的连接词只能有that吗？
不是的，其他疑问词也可以引导同位语从句，不过中学阶段一般只考查that引导的同位语从句。
如：You have no idea (how anxious we were then).
你不知道我们当时有多么着急。
The question (whether he should give it up) has been worrying him for days.
该不该放弃这个问题这几天一直在困扰着他。
上述例句中括号内部分即为同位语从句，它们都是用wh-疑问词引导的。
怎么区别表语从句和同位语从句？
首先，同位语从句、表语从句属于名词性从句，在语法上相当于一个名词。
1.同位语从句
顾名思义，从句跟它所对应的先行词是“同位”的，地位相同。一般由that引导。
例：I heard the news that our team had won.
句中news即为先行词，that our team had won即为同位语从句。本质上，先行词就等同于同位语从句，同位语从句呢就是对先行词进行补充说明。
2.表语从句
表语从句就是用一个句子作为表语，说明主语是什么或者怎么样的。通常在系动词be seem, appear, prove, turn out, grow 之后。连接词可以由that, what, who, when, where, which, why,whether,how.whoever，whomever，whichever ，whatever担当。
例句：
His suggestion is that we should stay calm. The question is when he can arrive at the hotel.
其实表语从句比较简单，如果是系动词 一个句子，那么这个句子就叫做表语从句。