英语中be\do\have这三个要怎么使用,我现在都分不清了,搞混了,

e 一般后接形容词或名词
do作助动词时,后接实义动词,作实义动词‘ 做’
have 作助动词时只有在‘现在完成时中出现’ have done ,作实义动词根据句意有不同的意思.
I am a student .
I am very happy .
Do you often go to school on foot
I have had supper .
He has supper at home .
Does he have supper at home