虚拟语气主句和从句的失态是怎么回事?尤其是有的时候从句或主句是hadbeendone或者是havebeendone

Question

虚拟语气主句和从句的失态是怎么回事? 尤其是有的时候从句或主句是had been done或者是have been done

Answer 1

从 句\x05 主 句
与现在事实相反\x05were / did\x05 would/ should/ could/ might + do
与过去事实相反\x05had done\x05 would/ should/ could/ might + have done
与将来事实相反\x05were /did would/ should/ could/ might + do
should do would/ should/ could/ might + do
were to do\x05 would/ should/ could/ might + do