Why is a question I usually ask my students, and most of my students usually get surprised and say, “Why??” when I ask them.
A student once said, “Foreigners like why.” I don’t know if that’s true and if Japanese don’t like asking why; but, for me, asking “why” when having a conversation with a person means that I am interested in that person.
It also makes a conversation longer because people who are not interested in each other will have nothing to say to or ask from each other.
For example, if someone tells me, “I couldn’t sleep last night,” and I just say, “Oh. Okay,” then the conversation ends and it for the person who is talking, it would feel like I wouldn’t care.
But if I said, “Why?” then it means that I am interested in the reason and maybe I am worried, and the speaker will feel that I care and I am listening.
On the other hand, when I ask my students “why”, I am basically giving them an opportunity to speak more, to practice more, to apply the vocabulary or grammar rules they know, to open their minds, and to make them curious and think for themselves.