Q.I don’t know the right Japanese words to say good-bye to people who are older than me. My friends and I usually exchange casual farewells, such as じゃあね （“See you later” or “Take it easy”） or ばいばい （“Bye-bye”）. Is it impolite for me to use these expressions with people who are older than I am?

A.Sayonara is an abbreviated form of polite farewells

  Both of these phrases entered the Japanese language fairly recently, and both are considered casual ways of saying good-bye. This casual farewell derives from two words ― じゃあ（which comes from では meaning “now” or “well”） and the sentence-ending particle ね. As neither じゃあね nor ばいばい ― a loanword regarded in Japan as an expression used by children ― is considered entirely respectful, it’s best not to use them on formal occasions or in conversations with people who are older than oneself. Instead, it’s safe to use さようなら（“good-bye”, “if it be so”） as a farewell. This commonly used word had many variants in the Edo period （1603-1867） : しからば, さようなれば, そんなら, etc. Also, people in those days tended to use some lengthy forms of さようなら（“if it be so”） to explicitly sound respectful. For example, they would say さようならば明朝お目にかかりましょう（“If it be so, I’ll see you tomorrow morning”） or さようならご機嫌よろしう（“With that, I’ll see you tomorrow”） or さようならおしずかに（“With that, I bid you a peaceful day”）. These expressions are rarely used today. For students who feel さようなら may not be deferential enough to say when leaving a company after a job interview, I recommend they say（それではこれで）失礼させていただきます（“Now please allow me to excuse myself”）. This is sufficiently polite.

published in The Japan News on 15/9/2015