1. "using a serious tune-up."
- This means to improve or to upgrade, to make something better. For example, 제 한국어를 could use a serious tune-up.
2. "what club does he work out of?"
(please explain of "he." I can't get who the person is. Rex? or Carlos? or Someone else like...tennis coach?"
And wanna know the whole meaning of this sentence)
- The "he" in this sentence refers to the tennis coach. He is a 3rd person pronoun, so he is not one of the two people talking. Since tennis coaches work in country clubs, Carlos is asking "어디에서 Tennis Coach 일해요?"
Thanks so much for ur kindly help!
- Hope I helped. 감사합니다!