Tom is cleaning the ciassroom.改为否定句
问题描述：
Tom is cleaning the ciassroom.改为否定句
答
Tom isn't cleaning the classroom.
陈述句变否定句在be动词、助动词或情态动词后加not
答
Tom isn't cleaning the classroom.
很简单啊，改否定句就是助动词加not就可以了啊
答
Tom isn't cleaning the ciassroom
如还有不懂的,还可以继续追问哦\(^o^)/~
答
Tom is not cleaning the classroom
is的否定式是is not
祝楼主更上一层楼