either是“也”用于否定句中的句末；neither 是“既不”本身是一个否定词,常和nor 搭配；both 是用于两者的“都”,如果三者或三者以上表示“都”要用all,so是因此、所以的意思,还可以当感叹词“真.,太.”,none 是“没有一个人的意思'也是一个否定词.
eg:1.she is not a student ,I am not a student ,either .
2.he likes neither red nor black.
3.tom and I are both good students .
4.tom john and I are all boys .
5.tom wasill ,so he didn't go to school .
6.none of us is playing .