1.can't you come in and have tea now?意思是你现在不能进来喝杯茶吗?使用了反义疑问的表达.can you come in and have tea now?是一般疑问句,意思是你现在能进来喝杯茶吗?
2.Will you go there?Won't you go there?
3.Don't you go there?是“你不去那儿吗?”有反义疑问的用法,回答回去,用 “Yes,I do."回答说不去,用“no,I don't."
do you go there,don't you这个表达是错误的,不管是否地道,语法上可以改成You go there,don't you?