[Nyororin]

Dreams in a language I do not know? Nope.

I dream in Japanese most of the time - even when it involves family or people who do not speak Japanese in real life... Or at the very least, I am speaking to them in Japanese and communication is happening.

It also tends to be the biggest thing that tips me off in a dream that it is indeed a dream. There will be a moment when I think, "Wait, so-and-so doesn`t speak Japanese..."

But I speak Japanese 99.999% of the time. My main exposure to English is the net, which certainly doesn`t involve any speech on my part.
I can`t really recall every having a dream that was in a language I do not know.