1. -기가 you are pointing out is actually -기-가. -기 is a nominalising suffix added to a verb stem in order to creat something like a gerund. -가 is a subject marker(or particle? it's 조사 in Korean. I'm not quite sure what it is in English.) So, 공부하기가 is 공부하-기-가, which means 'studying'(as a subject). 2. 어떻게 how 지내세요 = 지내-세요. 지내(다) kind of means 'to live', but not really. There's no corresponding English word for this. You'd better look up the dictionary for this one. Anyway, in this case, I think it could be translated into 'be doing' as in 'I'm doing fine'. -세요 is a interogative ending in informal, polite honoric term. Thus, 어떻게 지내세요? means 'how are you doing?'