effort表示努力的结果、有组织的活动、艰难的尝试等含义时，为可数名词，其复数形式为efforts，例如to make an effort去做出努力、the Russian space effort俄罗斯航天计划、a determined effort坚决的努力等；当其表示努力、费力、吃力等含义时，常做不可数名词，例如put more effort into your work更加努力地去工作。

相关例句：

1、I've no use for people who don't make an effort.

我厌恶那些不努力的人。

2、This study represents a major expenditure of time and effort.

这项研究意味着要耗费大量的时间和精力。

3、The work was done with the minimum amount of effort.

做这项工作没费什么劲。

4、He made a concentrated effort to finish the work on time.

他全力以赴以按时完成这项工作。

5、The team's success was largely due to her efforts.

这个队的成功在很大程度上是她努力的结果。