妹(いもうと)さん

Polite reference form for someone else's younger sister — 妹(いもうと) + the honorific suffix さん. Do not use for one's own younger sister when speaking to outsiders.

Usage

• Used when talking about the listener's or a third party's younger sister
• For one's own younger sister (to outsiders): 妹(いもうと)
• Within the family, older siblings call a younger sister by name, not by 妹(いもうと)さん

Common collocations

• 妹(いもうと)さんはおいくつですか: How old is your younger sister?
• 妹(いもうと)さんによろしく: Say hi to your younger sister
• 妹(いもうと)さんとよく似(に)ている: looks a lot like your younger sister

Related words

• 妹(いもうと): one's own younger sister (humble; for outsiders)
• お姉(ねえ)さん: older sister (polite)
• 弟(おとうと)さん: someone else's younger brother (parallel form)