not very talkative
私の父は口数が少ない。
My father is a man of few words.
父は口数が少ないんです。
My father doesn't say much.
口数が少ないほど、訂正も早くできる。
The less you say, the sooner you can correct yourself.
彼は口数が少ない男だ。
He's a man of few words.