口で

実行するより口で言うほうが容易だ。

It's easier to talk about doing it than to actually do it.

口で言うのは簡単だ。

It's easy to say.

その絵は口で言い表せないほど美しい。

The painting is indescribably beautiful.

口で言えば分かる

You'll understand if I explain it verbally.

— ストーカー (1979)

口で言うほど簡単じゃない。

It’s not as easy as it sounds.