さん and ちゃん
おねえさん and おねえちゃん both mean ‘older sister’. The main difference is おねえさん sounds more formal than おねえちゃん.
さん sounds more polite than ちゃん.
お姉さん (o ne e sa n)
- お姉さん is a pretty formal word so people do not usually use it in their family.
- Some people use お姉さん in their family if they have strict parents.
- You should use お姉さん when you refer to somebody else’s older sister.
Vocabulary: Somebody else's family
On this page, you can learn how to say people in a somebody else's family in Japanese.
お姉ちゃん (o ne e cha n)
- おねえちゃん is often used when you call your own older sister as you don’t have to be polite or formal in your own family.