Looking up...
Younger brother
私の弟は小学生です。
My younger brother is an elementary school student.
弟はサッカーが好きです。
My younger brother likes soccer.
Used to refer to one's own younger brother or someone else's younger brother.
When referring to someone else's younger brother, use '弟さん' to be polite.
In Japanese, family terms like 弟 are often used with possessive particles (e.g., 私の弟) to clarify who you're referring to.
The kanji 弟 consists of '兄' (older brother) and '小' (small), literally meaning 'smaller brother'.
When referring to someone else's younger brother, it's common to add 'さん' for politeness.