Terms for subject Informal containing Could Have

English	Russian
A monkey could have seen it	и слепой бы заметил (использовано в речи британца Екатерина Диденко)
could I have a word in your ear?	можно с вами поговорить наедине? (Может употребляться сокращённый вариант: "A word in your ear, John? It's about those new contracts we mentioned.")
I could have died of shock	я чуть было не помер от страха (Andrey Truhachev)
I could have done with something	я бы (тогда) не отказался от (ч-л; выражение неосуществленного желания denghu)
there was no way someone could have + past participle	никак не мог (Paulides recounted how Robinson seemingly vanished at around 3 AM while walking to his hotel one night. Despite an exhaustive search of the area, the man's dead body was not discovered until five days later when searchers spied it at the bottom of a cliff in a nearby town. Eerily, cell phone records indicate that Robinson likely fell to his death shortly after 3 AM on the night he disappeared and, Paulides stressed, "there was no way" he could have traveled the distance to where his body was found. coasttocoastam.com ART Vancouver)
who could have thought	кто бы мог подумать
who knows what could have happened?	кто знает, что могло бы случиться (Andrey Truhachev)
who knows what could have happened?	Бог весть, что могло бы случиться (Andrey Truhachev)
you could have fooled me!	мне так не кажется! (DariaChernova)