Пояснения от американцев когда они говорят:
«How’s it going»,
«How are you?»,
«What’s going on»,
How’s it going to end,
How’s it going so far
«The phrase «How’s it going» is a common informal greeting and is the same as «How are you?»
If I were meeting someone like an important politician or the owner or president of the company I work at, «how are you» would be appropriate but «how’s it going» would not.
«How’s it going» would be a phrase when talking on ты.
«What’s going on» is similar to «how’s it going» but can either be a greeting or a question if you don’t understand circumstances. If I get home and there are several people in my house I would go to my wife and say «what’s going on.» On TV shows if a boss opens his door and one of his employees is looking in his desk, the boss will say «what’s going on?»
How’s it going to end — чем/как всё закончится? /о выборах Клинтон — Трамп/.
How’s it going so far — как у нас дела? /шеф спрашивает сотрудника/.
«How are you» would refer to how someone’s emotions are, or how their day has been.
«How is it going» would refer to just someone’s day, or what their currently doing» (C)