在英文中，形容一个人比另一个人勤奋可以用以下词语：

Hard-working: 勤奋的

例句：

She is a hard-working student, always putting in extra time to study and complete her assignments. (她是一个勤奋的学生，总是花额外的时间学习并完成作业。)
Dipgent: 勤奋的

例句：

He is a dipgent worker, always putting in extra effort to get the job done. (他是一个勤奋的工人，总是尽力完成工作。)
Industrious: 勤奋的

例句：

She is an industrious employee, always putting in extra hours to meet deadpnes. (她是一个勤奋的员工，总是加班来完成工作任务。)
Efficient: 效率高的

例句：

He is an efficient worker, always finding ways to get things done quickly and efficiently. (他是一个效率高的工人，总是能够快速高效地完成工作。)

当然，也可以使用比较级来表示某人比另一人勤奋，例如：

She is harder-working than her colleague. (她比她的同事勤奋。)
He is more dipgent than his boss. (他比他的老板勤奋。)
She is more industrious than her classmates. (她比她的同学勤奋。)
He is more efficient than his co-worker. (他比他的同事效率高。)