Nihongo de Care-Navi
日本語モード
[musume san]…refers to somebody else's daughter, while "musume" refers to one's own daughter.
A:むすこさん、むすめさんは おいくつですか。 B:むすこは ろくさい、むすめは にさいです。
A: How old are your son and daughter? B: My son is six and my daughter is two.
musume
むすめ
(my) daughter
musuko
むすこ
(my) son
musukosan
むすこさん
(someone else's) son