Hadde ikkje fasanen skrike opp, hadde han ikkje blitt skoten.
Had the pheasant not screamed it would not have been shot. [So keep quiet and refrain from unwise remarks.]
Han veit ikkje ein gong om potetene er kokte eller ikkje.
He doesn't even know whether the potatoes are boiled or not. [He lacks common sense. About someone who is not aware of what is taking place under his very nose.]