to occur or take place, especially without being planned
No one expected the power cut, but it happened during dinner.
Strange things happen in this old house at night.
to occur to or befall someone or something, especially something unexpected or negative
What happened to your arm? Did you hurt yourself?
A funny thing happened to me on the way to work.
to do or experience something by chance, often followed by an infinitive
I happened to see your sister at the market yesterday.
If you happen to find my keys, please call me.
