Talking in Your Sleep

My cousin Oliver talks in his sleep, but he doesn't make sense. He just kind of speaks a weird language that I don't understand. So my friend would wake up and look at his girlfriend sitting bolt upright in bed talking as if there was someone sitting on the end of the bed. And it became clear she was talking to her grandfather. It's not very common that people sleepwalk, but it does happen. But it must have freaked out my friend when, for example, he woke up, she wastalking to someone, she got up and seemed to leave the room talking.