@demonhunter,
My language understanding is such that I can identify dutch when it is spoken or written, but I cannot speak or write it myself.
So I know dutch. I know it when I encounter it.
But I do not speak it, so I do not know dutch.
See? The truth of the statement "I know dutch" depends on the context. Which context I will put it in at any given time is decided arbitrarily, in this case by me.