Now that you mentioned, I don't remember a single instance of a person speaking in my dreams. But I can't figure out if it was just a lack of language as general or if people communicated telepathically.
I've definitely had dreams with people speaking to me, but even in a language I'm learning -- the strange thing is that I can remember struggling to parse and comprehend what they were saying, as if their level of speaking ability was a bit higher than my own.
Either way... that's unsettling.