I have failed to reach them by postal inquiries.

我未能通过邮政查询与他们取得联系。

《新英汉大辞典》

I know then that I have failed to explain things properly.

一听到这种回应，我就知道我没有把事情表达清楚。

youdao

My goal is to help my team to win and since I haven't done that, I have failed.

我的目标是帮助我的球队获胜。但是我没有做到。我失败了。

youdao

I completely failed to understand the depth of the kind of cultural transformation that we were going to have to make it we were ever going to deal with climate change."

VOA: standard.2010.04.21

So if in fact I wanted to make sure this was a number, I should have done something like either try and convert it to a number, which of course failed here, or put in a check to say where it is.

因此实际上如果我想确保,这是一个数字的话，我们的课程上的代码,在这里失败了，你或许应该在这里，放一个检查的东西。

麻省理工公开课 - 计算机科学及编程导论课程节选

Note that I have failed to mention AutoZone (NYSE:AZO), a widely-followed auto parts concern.

FORBES: 3 Auto Parts Stocks: Upward On The Value Highway

This is not a situation in which I have failed to persuade the American people of the rightness of our position.

WHITEHOUSE: Presidential Press Conference on Tax Cuts and Unemployment Extension | The White House

One of the reasons I have failed to do these things is my confusion about whether I am using Twitter for personal or professional reasons.

FORBES: 4 Ways To Use Twitter To Find A Job