Nihongo de Care-Navi
日本語モード
[musuko san]…refers to somebody else's son, while "musuko" refers to one's own son.
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.
musuko
むすこ
(my) son
musume
むすめ
(my) daughter
musumesan
むすめさん
(someone else's) daughter