하소연을 하다 vs 불평하다 vs 투정을 부리다 Hi, so I was curious about how you would say "to complain" in Korean and in the dictionary, the following three words came out: 하소연을 하다, 불평하다, and 투정을 부리다. Do all three mean the same thing and are they interchangeable in usage? If there are differences, please explain!! Thank you very much.