Billy can not (upside-down).but he likes(playing football）with his friend (after class) 何处有错

upside-down是形容词,can是情态动词,情态动词后是接动词的,不能直接接形容词.课后的翻译不是after class是after school.所以我找出这两出错.还有弱弱的说一句,我真没看出来这两句话那里有转折的关系要用but.所以语法应该就前面两处错误了吧~那Billy can not (upside-down).该怎么改如果要用upside-down的话，前面最好价格be。Billy can not be upside-down。这样就可以了。