you had better do exercise ,後面跟倒裝句是什麼?有的人說是hadn't you有的說won'

題目：

you had better do exercise ,後面跟倒裝句是什麼?有的人說是hadn't you有的說won't you 到底正確的是什麼

解答：

當然是won't you
had better是最好去做什麼事.指還沒有做的事,
並不是過去式.