"To work hard" is a common Engpsh phrase that means to put in a lot of effort or to make a strong effort towards achieving a goal.
来源：这是一个常见的英语短语，意思是在实现目标方面投入很多努力或付出很大努力。
Example sentences:
I need to work hard if I want to pass my exams.
(我如果想通过考试，就必须努力工作。)
She works hard to provide for her family.
(她为了养家糊口努力工作。)
He is always working hard to improve his skills.
(他总是努力工作，提高自己的技能。)