弟は静かな性格で、あまり自分から話さない。
My younger brother has a quiet personality and doesn't talk much on his own.
彼女は教室ではいつも静かだが、友達の前ではよく笑う。
She is always quiet in class, but she laughs a lot in front of her friends.
先生は怒らずに、静かな口調で生徒を諭した。
Without getting angry, the teacher admonished the student in a calm tone.