What happen to you? 무슨 일이에요? Is he okay? 그 사람(그 분 in honorifics, 걔 between close friends) 괜찮아요? how did you make it? 어떻게 만들었어요? 어떻게 만드셨어요? in honor.. 어떻게 만들었어? between..

무슨 일이지요? (그 사람은) 잘 있지요? 이것을 어떻게 했지요?

To me, the answer of Richardus sounds more natural. The sentence, Is he OK? wouldn't be mentioned so suddenly, probably people would have talked about him in any ways. Blah, blah, blah... By the way, is he OK? or How is he? I would say, 잘 지내죠? 잘 있죠? 괜찮아요? formal / 잘 있지? 잘 지내지? 괜찮아? informal. Without the subject, because we've been talking about him, we all know who he is. And, "make it" might mean 하다 (성공하다) in the sentence. If I were the speaker in the conversation, I would say, 어떻게 하셨어요? or 아니, 그걸 어떻게 하신 거죠? formal/ 어떻게 했어? or 아니, 그걸 어떻게 한 거야? informal In this case, I do put the object in the sentence, but with or without, almost the same, I think. "아니" dosen't mean not or no in the sentence, actually, it has no specific meaning, but it's often used at the beginning of sentences to emphasize a little, Oh! or Wow! Korean stences could be translated in slightly different ways by Korean native speakers, which would make foreign people confused, but this is the Korean language. It's important to have your own style as you are learning. Good luck!

the previous answer is also WRITE > RIGHT*

*what happen to you? 무슨 일 있어? (to friend, or younger person) mu-sn nil ii-seo? 무슨 일 있으세요? (to stranger, older person) mu-sn nil ii-ss-se-yo? *is he okay? 그 사람 괜찮아? (to friend, or younger person) g sa-ram guen-cha-na? 그 사람 괜찮아요? (to stranger, older person) g sa-ram guen-cha-na-yo? *how did you make it? 이거 어떻게 한거야? (to friend, or younger person) ii-geo eo-tteo-ke han-geo-ya? 이거 어떻게 한거에요? (to stranger, older person) ii-geo eo-tteo-ke han-geo-e-yo? well the previous answer is also write but I wrote these in spoken language.