as well 与too 用法类似,都用在肯定句,并位于句末,too经常是和句子隔开,而as well 不必,例如 He likes chocalate as well./ He likes chocalate,too.
as well as 与not only...but also 意思差不多,都是不但,而且的意思,但主谓一致是需要注意,例如 I,as well as my parents,am going to visit my granny this weekend.（谓语和I 保持一致）
Not only he but also Tom are doctors.(谓语用复数)