아무 사람이 없다. -> nobody is (here,there, etc) 아무 사람도 없다 -> nobody else is (here,there,etc)

first clear this .아무 ->this word is not using commonly ,because just you know, there is no correct way to use, even slnag or dictionary, only handful of local use, 사람이 없다->it is focus human, there is no residence , imagine! you visit town, and there is no sign of people, that is how it is 사람도 없다->it is focus air ,or condition, there is no sign of living creature, you are in town no sign of living creature, no pet, bird..etc...creepy ...in case you use this one, you are clearly alone.

Ой, я даже не знаю, о чем ты))) К экзамену, батенька, готовиться надо)

осмелюсь предложить еще один пример - no fucks were given that day = 아무 것이, not a single fuck was given that day = 아무 것도.. кажется я слишком много времени провожу на 9gag.com ))

Образное донесение грамматич материала значительно облегчает жизнь студента)). Вроде, дошло. Много раз спасибо)