有一种情况可以补充：当 every 后面接有数词或few时，数词或few后面可以接复数名词。如：
1. We meet every few days. 我们每隔几天就会一次面。

2. Every few days there seemed to be another setback. 每隔几日似乎就有一次挫折。
3. We take classes in chemistry every three days. 我们每隔两天就上化学课。
4. You must take your medicine every two hours. 你得每两小时服药一次。
5. The Olympics are held every four years. 奥林匹克运动会每4年办一次。
6. According to the American Constitution, Presidential elections are held every four years. 按照美国宪法，总统每4年选举一次。
7. I’ve been having violin lessons every two weeks, but I think I’ll make it every week from now on. 我一直是每两个星期上一次小提琴课，但是我想从现在起每个星期都上课。
8. Our college class has a reunion at the college every five years. 我们大学时的同学每五年在大学重聚一次。
9. One in every ten children now suffers from asthma. 现在有十分之一的小孩患有哮喘病。
10. She only sees her parents once every six months. 她每半年才探望一次父母。

注意：each 没有类似的用法。