这个分三种情况：
动词是系动词：变一般疑问句把系动词提前，否定句在系动词后加not.单三形式is.（常见系动词am,is,are)
肯定句：He is a worker.
疑问句: Is he a worker?
否定句：He isn't a worker.
特殊疑问句：What is he ?（ 对worker进行划线提问）他是干什么的？（问职业）
实意动词：变一般疑问句句前加助动词do,does. 否定句在动词前加don't,doesn't..单三形式动词后一般加s,es.
肯定句：He likes English.
疑问句: Does he like English?
否定句：He doesn't like English.
特殊疑问句：What does he like ?
情态动词：变一般疑问句把情态动词提前，否定句在情态动词后加not.单三形式不变.（常见情态动词can,may,must,need.)
肯定句：He can swim.
疑问句can he swim?
否定句：He can't swim.
特殊疑问句：What can he do ?
希望能帮到你。