French phrase
Je suis navré.
Meaning
I'm sorry.
When to use it
A formal, apologetic expression. It may sound somewhat heavy with close acquaintances.
Example dialogue
Je suis navré. Je n'ai pas vu ton message.
I'm sorry. I didn't see your message.
Ce n'est pas grave, je viens de le lire.
It's okay, I just read it.