We have tried this out many times, but have failed every time.

这办法我们试过多次，但每次都没有成功。

youdao

We are always seeking to improve productivity, but have failed several times.

我们一直试图提高生产率，但几次都失败了。

youdao

Both parties have suggested working together on the project but have failed to agree on details.

双方都建议就这一问题合作，但在具体问题上存在分歧。

youdao

He also asserted the United States and other nations have tried to isolate Iran for the last 30 years, but have failed and will continue to fail.

VOA: standard.2009.12.07

But,during the past three years, some have failed to fly south.

VOA: special.2010.03.02

But he added that U.S.policies to force change on the island, including an economic embargo, have failed to bring about democracy.

VOA: standard.2009.04.19

Blackburn won their only Premier League title in 1995 but have failed to challenge since.

CNN: STORY HIGHLIGHTS

Scotland did draw 12-12 with England at Twickenham in 1989 but have failed to win on their last 12 visits there.

BBC: Six Nations final day as it happened

Other economic systems have been innovative enough, but have failed to exploit their innovations or have had big firms but no incentives to innovate.

ECONOMIST: Economics focus