一到英文单选题I don't think he could have done such a stupid thing
1个回答

think suppose believe 在宾语从句(he could have done such a stupid thing last night)否定时 否定提前到主句所以don't think

但基于主语不同分为两类

1、主语是i 对从句提问 那么疑问根据从句来 先把否定词返回couldn't have done 这个结构是虚拟表猜测 (类似的有mustneed shouldought tomaybe able to have done) 所以提问 按照该句本来应有的时态did such a stupid thing last night 所以did he

2、主语非i只要对主句提问就行