Interrogative
It asks about
Examples
كَيْفَ
condition or manner: how?
كَيْفَ أَنْتَ؟ — How are you?
كَيْفَ حَالُكَ؟ — How is your condition?
أَيْنَ
place: where?
أَيْنَ أَخُوكَ؟ — Where is your brother?
أَيْنَ الْمَقَرُّ؟ — Where is the place of settlement?