言こと葉ばを尽つくす

expression, godan verb (-su)

exhaust one's words; use every possible word

Used when someone tries everything they can say to persuade, explain, or express something, often implying they have run out of effective words. Can also imply being overly verbose or talking excessively.

• 彼かれは言こと葉ばを尽つくして説せっ得とくしようとしたが、相あい手ては聞きく耳みみを持もたなかった。

  He tried to persuade them using every word he could, but they wouldn't listen.

• 感かん謝しゃの気き持もちは言こと葉ばを尽つくしても言いい表あらわせない。

  No matter how many words I use, I can't fully express my gratitude.