I 用 am ， you 用 are
is 用在单数 this ， 还有--- 他/她/它
~this is /he is /she is / it is
凡是复数都用 are
you are/ we are/they are
～别忘了these ， those 也是复数都用 are
these are/ those are
记住了，大家一起拍手笑哈哈！
l do /you do /we do /they do — 嘟，嘟，嘟
he does /she does /it does — 哒日，哒日，第三人称单身用 does !
