am is are是系动词(be动词 )翻译成中文就是“是”
I am Chinese.
He is a teacher.
You are so kind.
do可以作实意动词和助动词.实意动词翻译过来就是“做”,比如do my homework做我的作业
助动词通常用于
1.构成否定和疑问句
I do not like eating vegetables.我不喜欢吃蔬菜.
Do you like eating vegetables?
What do you like to eat?
现在时第三人称单数时用does,过去时用did
2.强调句
I do like maths!我确实喜欢数学!
现在时第三人称单数时用does,过去时用did
以上是do助动词的用法,do后面的动词用原形
希望有帮到你