Informal:
* Hé! - This is the most common and straightforward way to say "hey" in a casual setting.
* Eh! - This is another informal option, similar to "hey" but with a slightly more surprised or questioning tone.
Formal:
* Salut! - This is a more formal greeting, similar to "hello" or "hi".
* Bonjour! - This is a very formal greeting, used in most situations where you don't know the person well.
Note: "Hey" is not directly translated as "hé" in all situations. It is more common to use "hé" as an attention-getter or exclamation.