Is he three years old?Yes,he is.No,he isn't.He isn't three years old.
be动词的一般疑问句是把be动词拿到主语之前.
在美国英语中,have是一般动词,所以不能拿到主语之前,要借助于助动词do和does.
Does she have an orange?Yes,she does.No,she doesn't.She doesn't have an orange.
Do you have boxes?Yes,we do.No,we don't.We don't have boxes.
希望我能帮助你解疑释惑.