wow.....that's the best answer i have had..thanks so much ..i shall remember..

There are lots of ways to great in Vietnamese language and it depending who you are talking to. For example : You are 30 years old : 1 - 7 = Chào con, Chào cháu 8 - 29 = Chào em 30 = Chào bạn or Xin chào 30 - 49 = Chào chị ( Female), Chào anh (Male) 50- 65 = Chào cô ( Female), chào chú (Male) ( but sometime Vietnamese people will call " Chào chị" or " chào anh " just for please the others' sense) 65 - .......: Chào bà ( Female), Chào ông ( Male), or Chào cụ ( Female and Male) Quick notes: If you can't know exactly how old is she/he , you can use " Xin chào" ( in short) or " Chào + name" .( like the way you say " Hello , hi" or "hello + name" in English greeting). "Chào bạn" will be impolite with whoever are older than you ^)^ . They can accept it because you are a foreigner but if you want to be more friendly at the first time seeing you avoid to use it ^)^ . You can use " Xin chào" as the best choice in that case In fact, if you want your greeting make a sense , you can use "Em + Chào chị/ anh" and " Cháu / con + chào cô/chú/ cụ". " One more thing, you shouldn't use " Xin + chào em/ chị/ anh/ cụ....." It's right but Vietnamese aren't use it....^)^

a boy your age, you can say "chao ong" if he is a closer friend (some time, boy and girl call "ong - ba" together when they are closer friend). But if he is new friend, I think you should say "chao ban".

U can say:chao anh or chao ban in that case. Chao ban is more friendly & normally

"Chào Ông" with old men is best , it also uses in some formal conversation such as interview or talking with someone who are working in government,although they are in the same age with you. But "Chào Anh" is suitable in normal conversation, more friendly and I think some men like that way. ^.^ ^.^. Anyway "Chào bạn" is good at the first time ..