1.also可用在动词以前,也可用于句末.eg.We also went to see the film.我们也去看了电影.If you will stay,I will also.如果你留下来,我也要留下来
2.too只能用于肯定句句末.eg.I like bananas,but I like oranges,too.我喜欢香蕉,可我也喜欢柑橘.
3.either 也（不）用于否定句
I haven't read it and my brother hasn't either.
我没有读过,我兄弟也没读过.
4.neither‘也（不）用于否定句
I can't swim!’ ‘Neither can I!’
“我不会游泳!”“我也不会!”