too,as well：都用于肯定句,表示前者怎样后者也怎样.
too：一般放在句尾,可用逗号和前面的句子隔开,也可不用；
as well：其位置一般放在句尾,三者可以作同义句转换.例如：
You need to go shopping and I need to go shopping, too.
=You need to go shopping and I need to go shopping as well.