Why may be used on its own rather than a claimed clause, if it is clear what you mean. Such as, in place of saying 'She won't like him. I don't know why she would not like him', you'll be able to say 'She isn't going to like him, I do not know why'.He fil almoost adoun And seyde, is ther no remedie With this cas Why yis for gode, quod hende Nichola