I do not understand, why is this not translating into "walks in the sleep" (due to sömnen). And therefore why "in his sleep". Wouldn't that translate into "i sin sömn"?
so, "walk in the sleep" would be a correct meaning in swedish, but in english there is a set phrase for it and it would be wrong. I thought this was a course to learn swedish...
Using correct english in a english-to-swedish course sounds logical to me. What's your problem? I'm not native english and find it rather useful because it also corrects my english and I can learn both this way. Sure, it's a little more complicated but that's fine with me.