had been只是is的过去完成时么?怎么把 It had been a good day 改成疑问句?have been to 是不是固定搭

题目

had been只是is的过去完成时么?怎么把 It had been a good day 改成疑问句?have been to 是不是固定搭
I have been to the US.意思是我去过美国.这句话是现在完成时态,可是改成一般现在时就变成了 I is to the US.感觉好奇怪.
I have been a good boy.意思是我曾经是个好男孩,改成一般现在时是 I am a good boy.
却没有问题.
都是I have been 为什么一个可以改成现在时,一个不可以?是have been to是固定用法 还是be to,或者2者都不是固定搭配!

答案

had been只是be[系动词是]的过去完成时.It had been a good day 改成疑问句had it been a good day?
have been to 是固定搭配,表示曾经去过某地.【不能直接变成一般现在时态】