how to use 'I'm sorry'.

I want to know the way of using that phrase, and each meaning in every situation.
It's ok to use in casual or literal meanings, etc.

See a translation

By definition of words, "I'm sorry" just means that you feel regretful about something that has occurred.

However, the way people use it in most cases is as a default response to making a mistake. It means that you humbly admit that you are at fault for something while simultaneously excusing yourself from the consequences of your mistake.

You can use the expression in any context, just be mindful of the tone of your voice and make sure it's appropriate for the context. I have a friend who says sorry to me way too often for things he didn't even do, but some people only say it after an extreme blunder, so it's really up to you to decide what contexts you feel it's appropriate to use it in!