[Korean grammar] -기로서니 Expressing Causes and Reasons

가: 소피아 씨, 지난번에 바람맞혀서 미안해요.
Sophia, I’m sorry I stood you up last time.
나: 아무리 바쁘기로서니 못 나온다고 전화도 못 해요?
Couldn’t you at least have made a phone call to let me know you couldn’t come no matter how busy you were?
가: 그날 회사 일 때문에 정신이 없어서 연락을 못 했어요. 요즘 너무 힘들어서 회사를 그만뒀으면 좋겠다는 생각 마저 들어요.
I was really stressed out from work that day and wasn’t able to call. It’s so hard these days that I’m even thinking it might be better if I quit my company.
나: 회사 일이 좀 힘들기로서니 그만둔다는 말을 그렇게 쉽게 하면 안 되지요.
No matter how hard-working the company may be, you shouldn’t talk about quitting so easily.

-기로서니 is used when indicating that while the speaker acknowledges the fact stated in the preceding clause it is insufficient as a reason or condition for the action or state of affairs given in the following clause to occur. It denotes a meaning of excessive degree concerning the following clause and thus is often used together with 아무리.

가: 이번에 한 실수로 회사에서 해고될까 봐 걱정돼 죽겠어요.
I’m extremely worried that I will be fired from my company for the mistake I made.
나: 실수를 좀 했기로서니 그만한 일로 해고를 하겠어요?
While you made a mistake, why would you be fired for such a trivial thing?

가: 선영 씨가 우리가 생일 선물로 준 스카프를 자기 취향이 아니라면서 민아 씨에게 줬대요. 우리 앞에서는 그렇게 예쁘다고 하더니 말이에요.
I heard that Sunyoung gave the scarf that we got her for her birthday to Mina and said that it didn’t fit her tastes. She pretended she liked it very much in front of us.
나: 아무리 선물이 마음에 안 들기로서니 선물을 준 사람들의 성의가 있는데 정말 너무하네요!
Regardless of how much she may dislike a gift, there’s still the sincerity of those who gave it to her, so I think she went a little too far!

가: 엄마, 내일 그 가수 콘서트에 꼭 가고 싶어요.
Mom, I really want to go to that singer’s concert tomorrow.
나: 아무리 아이돌 가수가 좋기로서니 학교도 안 가고 콘서트에 간다는 게 말이 되니?
No matter how much you like pop stars, you can’t go to a concert without first going to school.