I'd love to come, only I have to work.

我很想去，但是我要上班。

《牛津词典》

I have to work hard today.

今天我得努力工作。

《牛津词典》

Now I have to work very hard next semester to keep my scholarship.

现在我下学期必须非常努力工作，以保持拿奖学金。

youdao

Madam C.J.Walker explained it this way: "If I have accomplished anything in life, it is because I have been willing to work hard."

VOA: special.2010.03.28

I mean, they have no idea how hard we work, and look at this gigantic split infinitive, to dramatically help.

他们不知道我们有多么努力地工作，注意到这之间的巨大鸿沟，会有很大的帮助。

麻省理工公开课 - 固态化学导论课程节选

I have made a conscious choice that I can't drive to work, I do have a spot in the parking garage.

我都会故意,不开车上班，我的车,停在车库里。

普林斯顿公开课 - 人性课程节选

It moves just a few metres at a time, backed up from the entrance to a bridge across the Tigris that I have to cross daily to get to work.

BBC: Viewpoint: Bad case of Baghdadophobia

If I need to take a break from work, I have to take one.

BBC: Man holding head

There is much left to do and I am very sorry to have been put in a position where I am unable to continue this work.

BBC: Short's resignation statement