助动词后一定要加动词吗?还有在【Why are you always late for school?】中why为什么不能用do代替呢?

问题描述:

助动词后一定要加动词吗?还有在【Why are you always late for school?】中why为什么不能用do代替呢?
又及:【Why are you always late for school?】中的are不是现在进行时吗?
望懂得的前辈做个解答.

因为late为形容词,用be动词修饰be + 形容词,也可以be + 动词ing表进行时.助动词(do,did) + 动词原形如:He is late for school.be + 形容词He is going to school.be + 动词ingWhat do you want to do?助动词do + ...还想麻烦您一下,在一个有助动词的句子中,助动词后一定要加动词吗?是的,如He doesn't like English.doesn't 为否定助动词,like为动词原型Do you speak Chinese?Do 为助动词,speak为动词原型Would you like some bread?would 为情态助动词,like 为动词原型