In Yotsubato Ch. 1, Fuuka asks Ena:
I understand this to mean "Have you seen a strange kid?" But I'm a bit hung up on the negative form of the verb here. Why not ask:
Is there a difference in meaning or nuance?
I know that negative verbs in questions can be used invitationally or rhetorically as in:
But somehow this case seems different to me. Is it the same or related grammar pattern? Or is it a different pattern that someone can point me to?