1. get your feet wet. 경험을 얻다; to gain experience at doing something.
Have you decided to go to graduate school?
I enrolled in a night class for this semester. (등록하다)
I guess it is better to get your feet wet.
2. keep one's chin up 용기를 잃지 않다. 기 죽지 않다; to remain brave and keep trying.
Someone else received the position instead of me. I feel so disappointed.
Well, keep your chin up because someday your hard work will be rewarded.(보상받다)
3. at a premium 품귀상태인, 구하기 힘든;
wanted or needed, but is difficult to get or achieve and is scarce.
Space is really at a premium where I live.
4. It's my treat. 내가 (무엇을) 사 주다; to buy something special for another person.
Do you know how much those cost?
Don't worry. The lobster here is cheap. It's my treat.
5. up for (무엇인가를) 기꺼이 하려고 하는; willing and able to do or take part in an activity.
Would you like to go skiing this weekend?
Sure, I'm up for that!(기꺼이 가야지)