Answering the poster in a recent thread about the emphatic "... что бы они ни ...." construction, I found a native speaker's sample sentence (on otvet.mail.ru here) как бы поздно ты не пришёл, позвони мне. But looking at it again, I think I would have written как бы поздно ты ни пришёл ... I Googled both the constructions: "Как бы поздно ты ни" - 28,100 hits; "Как бы поздно ты не" - 43,500 hits. Are both ни and не interchangeable in this type of construction? Is it perhaps because "бы" is modifying the adverb "поздно" rather than the verb "пришёл" that either "не пришёл" or "ни пришёл" can be used here? I've checked the few previous threads on this construction, but this specific point doesn't seem to be addressed. Thanks in advance. Отвечать можно и по-русски.