if she wasn't so busy,she might have joined us.
If she had not so busy,she might have joined us
两者不一样.前者是过去那段时间忙,是一直忙的感觉
后者是过去的过去忙,时态不一样,所以意思也有差别哦!
If they hadn't given me a ride,i would still be standing in the rain
If they hadn't given me a ride,i would have still stood in the rain
前者错误,语法上讲了的,这个举止应该是虚拟句,对过去的虚拟,后者对