Use polite Japanese to be rude.
This is why Japanese gets more amazing the deeper you dive. Who would’ve thought?
Now some of you may know that using polite Japanese can make you sound slightly stand offish, especially with a situation among friends. This is an extension of that, and when it comes to friends, and especially family, you can easily turn stand offish into obvious rude.
1. Your friend tells you what you did wrong and you are annoyed and want to show it?
Oh really, is that so?
2. Your older sister tells you that you need to go to school already and you don’t want to listen anymore?
Okay, understood. I will go already.
3. Your friend yells at you and you want to give a phony and rude apology?
I humbly apologize. It will never happen again.
Because it is polite language you would never use with these people, it immediately stands out, and shows annoyance.
One major warning though. Depending on the phrase and situation, often an additional change in tone is required (to show sarcasm or anger), otherwise it may come off as repentance (you wouldn’t want that now!).
The best way to make sure it comes off with intended rudeness is to extend certain ひらがな way longer than they are supposed to be and change rising and lowering intonation. It takes practice to do this naturally. But once you get it, you can improve your rudeness repertoire. And we all know how valuable that is!
Know of any other polite phrases that can be turned really rude?