fewer作形容词意为“较少的”、“不多的（few的比较级）”、“很少”、“（与复数名词和复数动词连用）有些”，所以fewer修饰可数名词。

few的用法

1.（与复数名词和复数动词连用）不多，很少

（1）Few people understand the difference.

很少有人了解这个差别。

（2）There seem to be fewer tourists around this year.

今年来访的旅游者似乎少了。

（3）Very few students learn Latin now.

现在学拉丁语的学生少得很。

2.a few（与复数名词和复数动词连用）有些，几个

（1）We've had a few replies.

我们已得到了一些答复。

（2）I need a few things from the store.

我需要从商店买些东西。

（3）Quite a few people are going to arrive early.

相当多的人打算早到。

（4）I try to visit my parents every few weeks .

我尽量每隔几个星期看望一次父母。

fewer的用法

（1）The report shows that fewer couples are getting hitched.

报告显示，结婚的人数呈下降趋势。

（2）We need fewer organizers and more doers.

我们需要的是少些组织者，多些实干者。

（3）He was advised to smoke fewer cigarettes and drink less beer.

有人劝他少抽烟、少喝啤酒。