____ you at home last night?为什么 要用were不用did?

问题描述:

____ you at home last night?为什么 要用were不用did?

如果变成陈述句,就是You were at home last night.at home算个形容词短语了,前面有人称代词的话,就要跟be动词……

be at home是一个短语.
作为疑问句,be动词的各种谓语变化要放在主语的前面.
come,go,arrive,meet的助动词是do/ does / did ..