Our Great Larry Kudlow, who has been working so hard on trade and the economy, has just suffered a heart attack. He is now in Walter Reed Medical Center.
这是特朗普最新的twitter，译文是：大家伟大的拉里·库德洛，一直在贸易和经济方面工作努力工作，他刚刚突发心脏病，现在在沃尔特里德医疗中心治疗。 在什么方面是努力工作应该是work hard at吧， 和work hard on的不同之处?
work hard at 和work hard on，应该是一对同义词组。有时可以互换用，但侧重点一直有所不一样的：
1. work hard at 主要指“学习用功”，后面的宾语多与“学业、学科”有关，还可以是“任务、目的”等。
I have worked hard at my major subject. 我对主修课特别用功。
He is working hard at this thesis. 他正在努力地写作论文。
I studied art and worked hard at it. 我学艺术,而且非常用功。
Characteristically, he worked hard at the assignment. 他一如既往地认真完成分派的任务。
2. work hard on 主要表示“致力于”，后面的宾语范围较广。比如，“致力于大小所有事务”。大到“经济、贸易、外交、建设、工程”，小到“编故事、打游戏”等。work hard on 常常可以接动名词，指具体的动作事件。
Our Great Larry Kudlow, who has been working so hard on trade and the economy, has just suffered a heart attack. He is now in Walter Reed Medical Center.
大家伟大的拉里·库德洛，一直在贸易和经济方面工作努力工作，他刚刚突发心脏病，现在在沃尔特里德医疗中心治疗。
And we expect them to work hard on the federalism issue.
并且大家盼望他们致力于解决联邦制问题。
All he did was sit back and watch others work hard on the project.
他只是轻松地看着别人为这个项目努力工作。
Theyarewilling toworkhardonachievingtheirgoals.
大家非常乐意于为我们的目的努力奋斗。
He was working hard on playing the game.
他正在拼命地打游戏。
