Not only…but also…用来连接两个并列成分

1.当not only…but also连接两个句子，并且not only位于句首时，第一分句部分倒装，but also后的句子正常语序。

eg.Not only does he study hard,but a he is also always ready to help others.

2.not only…but also还可以连接其它相应成分。当连续主语时，谓语动词遵循就近原则。

eg Not onlythe teachers but also the teacher was invited to the party.不仅学生被邀参加聚会，那位先生也受到了邀请。（连接主语）

He is not only my teachetbut also my friend.他不仅是我老师，还是我朋友。（连接表语）