简析also, too, as well和either用法
also, too, as well, either,作“也”讲，为副词。下面分别讲述：
too：一般放在句尾，可用逗号和前面的句子隔开，也可不用；
also：其位置大多放在be动词、助动词、情态动词之后，实义动词之前；
You need to go shopping and I need to go shopping, too.
=You need to go shopping and I also need to go shopping.
=You need to go shopping and I need to go shopping as well.
