Ah! Well then, I will add Amharic, the official language of Ethiopia, as the greetings are something I can handle (well, most of the time....)
It is perhaps typical of the language that a video listing 'basic greetings' takes up twenty minutes (and I never heard the words listed as 'hi' here), but, well....
(I am including the video, because trying to figure out pronunciation based on my transcription isn't really straight forward - and the video has the words written using the fidel, as they should be. 'Is' is typically transcribed 'new' for English speakers, because it's more like 'noah' than simply 'no' - there's a 'w' without any additional vowel on the end. If you just say 'no', you sound funny to native speakers. But if I write 'now', most people wouldn't read that as no-w.)
Selam no? = Hello. [lit, Is there peace?]
Peace is-[there]?
Selam no, egsabier emasgen. = There is peace, thanks be to God.
Peace [there]-is, God/Savior thanksgiving (okay, okay, so I never really learned grammar in this language....)
Endate no? = How is it [going]?
How is-[it]?
Dena neñ, egsabier emasgen. = I am fine, thanks be to God.
Fine -am, God thanks
Dena neh/nesh/nachoo? = Are you (m/f/pl) fine?
Fine are-[you]?
Egsabier emasgen, dena neñ. = Thanks be to God, I am fine.
God thanks, fine -am.
Antes?/Anchis? = [And] you (m/f)?
You?(m)/You?(f)
Dena wal! = Goodbye! (lit., Have a fine day!)
Dena hun/huni/hunu! = Goodbye! (m/f/pl)
Ciao! = Goodbye (loan word from Italian)
The real trick with greetings is that they depend on time of day, but aren't simply 'Good morning' or 'Good night.' So, if you greet someone in the morning, you ask them how was their night. And if you greet someone in the afternoon, you ask them how their day was. Etc. Luckily, no matter what, the response is "I am fine, thanks be to God. And you?"
(There is also a formal/respect form of 'you' for all of these, but I never learned it. So I guess I was perpetually rude to older folks, oops.)
Other basic greetings:
Melkam lidet! = Happy Birthday! (This is expressing wishes that someone will have a happy birthday, so you would never use it after the fact for belated birthday wishes.)
Enquanaderaseh/Enquanaderasesh/Enquanaderachoo! = Happy feast (m/f/pl)! [IIRC]