恰好 (qià hǎo): ในขณะที่มันปรากฏ

I happened to pass by this bookstore, so I went in and bought a few books.

He happened to appear when I needed help.

We happened to sit in the same row, so we had a great chat.

The meeting happens to be scheduled on my birthday, what a coincidence.

I happen to have an extra dictionary that I can give you.