are, is , be , been.怎么的用法?

are:主语为 you,we,they以及其他所有复数名词
You are nice.
They are nice.
Apples are delicious.
is:主语为第三人称单数
It is nice.
The tiger is dangerous.
He is smart.
be:Don't be shy
Be brabe.
been:be 的过去分词,用于过去完成时等
I have been to that city.
I have been reading for one hour.
(这个理论挺难概括的)

1. are 用于“你”第二人称，或者复数人称后面：you are so kucky; we are good friends等等
2. is用于第三人称单数，如he/ she/ it is ............
3. be是助动词的原型形式，用于祈使句或需要动词原形的地方：Be quick ; it will be a nice day!
4. been 是助动词的...