i believe "nani wo iu tennan?" means "what are you trying to say?" or something along those lines, so that should work
ogenki desuka
Nani generally means why or what
Formal:なにをしていますか?Romanji - Nani o shite imasu ka? Informal:なにしている?Romanji - Nani shite iru?
You may say 'nani o shite imasu ka,' written in Japanese as: 何をしていますか
Who Am I?(A boy) "What am I?" would be more accurate, as 'nani' is literally 'what'.
The answer is Nani or 何"nani?" or "nan desu ka?"
何 - Nani
I don't know about any 'yansei' (with long e) but maybe what you are looking for is ''yanse' (with short e) which could be a conjugation of verb 'yansu', used informally and in some dialects, meaning 'to be'. E.g: Nani shiterun desuka? (What are you doing?) Nani shite yansuka? (same meaning)
Nani o shimasuka.
what does the phrase "Nani Loa" mean
I think the phrase you're looking for is "nani kore?" which is "what's this?" in Japanese.