i didn't know you had called the police before l came here

问题描述:

i didn't know you had called the police before l came here
为什么是didn't而不是don't

中文“我不知道……”后面只要跟的是陈述一件事,就要说 I didn't know...,因为跟在后面的事你不知道是过去,现在一定知道才会说.例如:我不知道你已来了.I didn't know you are here.如果后面跟疑问句,表示现在仍不知...