Were you at home yesterday evening?
did 是助动词,后面还要有动词才可以,而这句话中后面是 at home这个介词词组,要用系动词be
这里换成肯定句式是：You were at home yesterday evening.意思是昨天傍晚你在家.当转换成一般疑问句式就是把be动词提前