Nansai desu ka? Means what year is/was it? Nan=what Sai=year Desu=to be(is/was) Ka=questions particle. Its literal translation is "what year is?" the subject that you are talking about is implied by the context of the conversation.
koko de nani ga okkotte irun desuka
明日はひまですか? ashita ha hima desuka?
watashi WA ju san sai desu.
空襲火災 /kuu shuu ka sai/.
if you don't understand a word in a sentence, or even a whole sentence what does "hon" mean in English? - eigo de, "hon" WA nan desu ka? you could say i don't understand, wakarimasen, or ask for it to be repeated, mo ichi do kudasai
Eigo = English (language) Nan desuka = what is it? Usually, people say "Eigo wa nan desuka?" = "What is english (the language?)" Or, even more common: "Eigo de nan desuka?" = "What is that (whatever you said before) in English?" ie. "Can you please translate that into English for me?"
nanika hitsuyo desuka
I guess you could say 'sufficient/okay'.eg. Ikaga desuka? Is this okay?
Ogenki Desuka?
(Honorific) O-genki desuka? (do not pronounce the "u") Genki desuka? (formal) genki? (informal) Ikaga desuka? (use this when talking to someone you respect highly or do not know)
"What is this movie called" この映画の名前は何ですか。(kono eiga no namae wa nan desuka?) "What is the name of this movie in Japanese?" この映画の名前は日本語で何ですか。(kono eiga no namae wa nihongo de nan desuka?)
where is どこ (doko)eg. where is ~? = ~はどこ(ですか)   ~ WA doko desuka?note: as a polite form, we also have どちら (dochira).so, it'll be more polite if you say "~ WA dochira desuka?" than "~ WA doko desuka?"
Expression..................................Formality Level....................UsageGenki?...............................................Low................................ColloquialOgenki desuka....................................Standard..........................SpokenGokigen ikaga desuka...........................High................................Spoken*Ikaga osugoshi desuka........................High................................WrittenOngeki de irasshai masuka....................Very high..........................Written*Ikaga osugoshi de irasshai masuka........Very high..........................Written[* The two marked ones mean more like 'How have you been'.]
You may simply ask 何æ‰ã§ã™ã‹ (nansai desu ka) if you wanted to know the addressee's age in Japanese. In most cases you won't need to specifically use the word 'you', as it is assumed that if one is asking a question, it is directed at the listener.
Not exactly as slang as the English version, but 'ittai nan datte?' would be a close one.
treea nan elan
Sai fora!