Hi, We have the formal and informal form, so I'll translate your sentences in both form. "not a person" (formal) hito de wa arimasen (informal) hito de wa nai *you can also say JA instead of DE WA though DE WA sounds a bit more formal in each form. **Generally we write JA though JYA isn't incorrect. "there is not a person" "A person is not there" *I think both means the same although I'm not sure for my English. (formal) hito wa imasen / hito ga imasen (informal) hito wa inai / hito ga inai *there is no one / nobody is there (formal) dare mo imasen (informal) dare mo inai "There is not a person who is not there" ? *I couldn't understand this English sentence for my English. I hope this was helpful.

hmmm, are you good at math? I found the easiest to understand negation by using "≠" for jyanai. And let's put subject to more understandable. anata = you,, jyanai = not, iru = There is/are ~, inai = There is/are no ~. hito = a person/human, seito = a student, otoko = a man/men, onnna = a woman/women *most nouns can put 'jyanai' at the end and becomes adjective. 1) anata ha hitojyanai - you are ≠ human 2) hitojyanai iru - There are people who are ≠ human 3) hito inai - There are no people 4) hitojyanai inai = hito iru - There are no people who are ≠ human = There are people who are human Actually 1) to 4) is not a complete sentence, so even I'm hard to understand it!lol 5) anata ha otokojyanai - you are ≠man. 6) otokojyanai hito - A ≠man person. 7) seitojyanai otoko - A ≠student man. 8) onnnajyanai seito - A ≠woman student. 9) otoko ga iru - There is a man. 10) onnnajyanai hito ga iru - There is a ≠woman person. 11) seitojyanai onnna ga iru - There is a ≠student person. 12) hito ga inai - There is no person. 13) seito ga inai - There is no student. 14) seitojyanai otoko ga inai - There is no a ≠student man. 15) otokojyanai seito ga inai - There is no a ≠man student. 14) and 15) are double negative, so we don't use>< Did you get it?xD