Formal:
* Desculpe-me: This is the most formal way to say "I'm sorry" and is appropriate for situations where you are addressing someone of higher authority or someone you don't know well.
* Peço desculpas: This is another formal option that translates to "I apologize." It is slightly more formal than "Desculpe-me."
Informal:
* Desculpa: This is the most common and informal way to say "I'm sorry." It is used among friends, family, and people you know well.
* Me desculpa: This is another informal option that is similar to "Desculpa" but slightly more polite.
* Sinto muito: This translates to "I'm very sorry" and is used for expressing deeper regret.
Other options:
* Lamento muito: This translates to "I'm very sorry" and is similar to "Sinto muito" but slightly more formal.
* Fui mal: This translates to "I was wrong" or "I made a mistake." It is a more informal way to express apology and can be used for small mistakes or misunderstandings.
Choosing the right phrase:
The best way to choose the appropriate phrase is to consider the context of the situation and your relationship with the person you are apologizing to.
For example, you would use "Desculpe-me" if you accidentally bumped into someone on the street, but you would use "Desculpa" if you accidentally spilled something on your friend's shirt.