I was walking down the street when someone suddenly whistled at/to me.
Are both okay? If yes, is there a difference between them? Which one is more natural? Thank you.
If you whistle AT someone, it a quite rude thing to do.
The workmen whistled at the pretty girl.
It gives the impression of a "wolf whistle" or similar.
If you whistle TO someone, it is (for example) to attract their attention, perhaps someone you know.
I saw Jon across the street, but he didn't notice me until I whistled to him.