也可以修饰人，字典例句：

She was very effective in getting people to communicate. 她在让人们沟通方面很能干。

原句出自 the free dictionary. https://www.thefreedictionary.com/effective.

又例：

How effective are lawyers in solving legal problems? 律师解决法律问题的效率如何？(Longman)

She's a very effective teacher. 她的课教得很好。（Cambridge Dictionary)。

至于effective 如何翻译，要根据具体语境决定，但它的基本意思是：有效的。