This is the 3705th most frequent Japanese word.
お母さん
Mother.
In this sentence, 'お母さん' is used to refer specifically to the speaker's own mother in a respectful and polite fashion. It is often used in personal interactions to show endearment and closeness.
私はお母さんに手紙を書きました。
I wrote a letter to my mother.
Here, 'お母さん' is used to refer to someone else's mother respectfully. Adding the pronoun '彼の' (his) specifies whose mother is being discussed.
彼のお母さんは料理が上手です。
His mother is good at cooking.
The term 'お母さん' in this context addresses someone's mother directly with respect. It shows care and interest in the well-being of the addressee's mother.