He can swim.是典型的主谓句型即：S + V.主语是He;谓语由“情态动词can + 行为动词swim”构成。而so can I是所谓的倒装句型，即：So can I. = I can swim, too.
倒装句型
5.He can swin? 6.She can sing? 改成一般疑问句或否定句或否定回答 急急急急急急急!~ 1、Is he tine? -Yes,he is./ No,he isn
