主句和从句怎么区分,英语语法中怎么分主句和从句？

主语开头的就是主句，主句前不能有连词，那么有了连词就是从句了。主语是句子的中心，从名是修饰主句或句中的某些成分的，充当名词主句和从句怎么区分、副词、形容词用，将其改这相应的名词、副词、形容词亦可，如果去掉从句主要意思仍完整，如: That he is a student is true.可以将从句That he is a student 用it代替，即It is true. The book which is red is mine.可改成The red book is mine.用 red 代替从句which is red. I am a student when I was 7years old.可改成I am a student that time.用that time代替从句when I was 7years old。 The book (which)I bought yesterday is red.这句主要说的是:这本书是红的，去掉(which)I bought yesterday 意思还完整，所以(which)I bought yesterday 是从句。

这是指主从复合句，这才有主句和从句之分一般有两个谓语和主语。单独一个英语句子只有一个主语和谓语，是没有主从句的。 如， I like going to the library every sunday. 这是一个单独的句子，只有一个主语和谓语。 If you want to make progress, you must study hard. 这就是主从复合句，有两个主语和谓语，这里有连接词If, 所以有连接词连接的从句，后面的就是主句。

主从句时态一致原则是指：1.如果主句是一般现在时态或现在完成时态,从句常根据需要选择适当时态. 如：The teacher says that he will go to the Great Wall next week . He tells us that he had an accident the other day .

2.如果主句是一般过去时态,从句常用过去的某种时态；但从句如果是客观的真理或事实,仍用一般现在时态表达.如：He said that he would go to visit the Great Wall the next week . The teacher told us that the sun rises in the east .