"Forgive me."

[kahealani3030]

E kala mai is more often used as "excuse me" of "pardon me" to be polite not so much as an apology. Example: "E kala mai, you can please pass me the salt?"

[dman1007]

I agree with kahealani3030. I would also add that the more complete form of the expression is E kala mai i'au.