I know that he has tried hard; be that as it may, his work is just not good enough.

我知道他已经尽力了，尽管如此，他的工作仍不太理想。

《牛津词典》

It's just so hard to think about all of those practical things and make good work, you know.

你知道，要想把所有这些实际的东西都考虑进去并做好工作是很难的。

youdao

Just as a rolling stone gathers no moss, mobile people are hard to get to know.

就好比一个滚动的石块没有苔藓聚集其上一样，多变的人很难相互了解。

youdao

So I thought,'Okay then, stop thinking so hard and just do it,' 'cause I know I have it in me.

VOA: standard.2009.08.18

and just, you know, work hard and study, do your homework, eat well too, I'm sure that helps

所以，我的建议是，努力学习，认真完成作业，
同时也好好吃饭，这真的很重要哦。

如果是在考虑留学 - SpeakingMax英语口语达人

They just say, "It's just because!" It's hard to know exactly why it's "a".

他们只会说“没有为什么！”为什么用“a”很难确切搞清楚。

韩国人经常犯的失误 - SpeakingMax英语口语达人

And perhaps more than anyone else, I know just how hard this fight will be.

CNN: Clinton's September 17, 2007, speech on health care

And others say that Israel has to just, you know, hit hard these groups taking the soldiers and make sure it doesn't happen again.

NPR: Border Fighting Spurs Israeli Blockade of Lebanon

You know, it's hard to remember where we started just, you know, 15 months ago.

NPR: Obama Re-Writes History, Clinches Party Nomination