Quote Originally Posted by becksie
So п/ф/к/т/ш/с mutate to б/в/г/д/ж/з when they appear before л/м/н/р/й as well as б/г/д/ж/з ?
No.

Quote Originally Posted by becksie
I’m sure I read somewhere that it doesn’t happen before в though?
No, it doesn't. квас = kvas, Тверь = tver, свет = svet