too，also，as well，either的区别

　　too,also,as well,用于肯定句，表示后者和前者一样，而either,用于否定句。too,一般放于句末，可用逗号和前面的句子隔开。also, be动词，助动词，情态动词之后，实意动词之前。as well,一般放于句末。

　　1. too：较为口语化，用于肯定句或疑问句中。一般用于句末，或作为插入语放在句中，与前面的内容用逗号隔开。如：

　　Jim likes red. I like red，too.

　　吉姆喜欢红色，我也喜欢。

　　I like to play soccer, and she likes to play soccer, too.

　　我喜欢踢足球，她也喜欢踢足球。

　　I can play the piano and Mary, too, can play the piano.

　　我能弹钢琴，Mary 也能弹钢琴。

　　Are they coming, too? 他们也来吗?

　　2. either：用于否定句/否定意义的疑问句中，通常放于句末。如：

　　If he doesn't go， I won't, either.

　　如果他不去，我也不去。

　　It won't do them any good, but it won't do them any harm, either.

　　这对他们没什么好处，但也没有什么害处。

　　Don’t you like dancing, either?

　　你也喜欢跳舞吗?

　　3. also：较为正式，通常用于实义动词之前，系动词、情态动词和助动词后。用于肯定句或疑问句中。如：

　　I’m late for school, and Mike is also late for school.

　　I can speak English and I can also speak a little French.

　　I’m writing a short story, and she is also writing a short story.

　　She likes reading novels (小说) and I also like reading novels.

　　Do you also want to come with us?

　　4. as well：用于肯定句或疑问句中，通常放于句末。如：

　　He speaks English, and he knows French as well.

　　他说英语，也懂法语。

　　Can you help them with English as well?

　　你也能帮他们学英语吗?

　　口诀助记：

　　also用于肯定句， 请(情)主(助)席(系)后实动前。

　　too也用于肯定句，句末逗号别忘记。

　　as well 放哪里，肯定句末就可以。 (乖乖女，她在句末肯定你)

　　either either最叛逆，否定句末就是你。