口は

talking; someone’s way of speaking

→ 口
phrase Rare #34,333
talking; someone’s way of speaking Often appears in expressions describing how someone speaks.
JA: 口は達者だな。
EN: You’re quite the smooth talker.

彼女は口は悪いですけど根は優しい人ですよ。

She may have a sharp tongue, but deep down, she's a kind person.

口は堅い?

Can you keep a secret?

口は達者だな

You sure are good with words.

— ミッション・クレオパトラ (2002)