Emergency Chinese spelling lesson...

Ni Hao (nee how) = Hello / how are you? in Mandarin Chinese. Also "Ni Hao Ma?" 'How Are You?' with the pronounced question particle 'ma' (they say their question marks in Chinese)...

Chinese is also a tone language so what it means depends on how you say it, but 'ni hao' is understood no matter how you say it. But officially, the 'ni' is a rising tone or an already high tone because the 'hao' is said with a dipping then rising tone, ending with a high level tone for the 'ma' if you say it.

Zai Jian (literally "later/again see" as in "See you later" or goodbye. Said with a sharp downward tone on both words. almost sounds like you're scolding someone.

The 'z' in Zai Jian is more of a d-z sound as in the 'des' in Rhoades scholar...

Not to criticize anybody, just so's you know more than you did before.