I thought you had done it 怎样变反义疑问句

I thought you had done it,hadn't you?
含有think,believe,suppose,imagine,expect等动词后接宾语从句构成的主从复合句在构成反意疑问句时,视情况不同有两种不同的构成方式.
(1)当主句的主语为第一人称时,其后的简短问句应与从句相一致.例如：
I expect our English teacher will be back this weekend,won't she/he?
I don't believe that he can translate this book,can he?
(2)当主句的主语为第二、三人称时,其后的简短问句则应与主句相一致（此时,否定只看主句,与从句无关）.例如：　　Your sister supposes she needs no help,doesn't she?