N4
かな
I wonder
あの人が道の真ん中で倒れてるけど、大丈夫かな。
That person is lying collapsed in the middle of the street. I wonder if they're okay.
Explanation
「かな」 at the end of a plain-style sentence means 'I wonder …'.
1Talking to yourself when you are unsure: 「明日晴れるかな」 (I wonder if it will be sunny tomorrow); 「これでいいかな」 (I wonder if this is okay).
2When asking someone else, it is softer than 「か」 alone and puts less pressure on them.
Men and women both use it.
Mixed up with
「かな」: for everyone; the most natural for everyday self-talk.
「かしら」: traditionally used by women, with a soft tone: 「明日は雨かしら」.
「だろうか」: written or more formal self-questioning: 「これで十分だろうか」.