few的比较级和最高级分别是fewer, fewest。few的比较级和最高级用法：
1.few的比较级fewer，用于两者比较。
fewer than 比…少…
The T-shirt is fewer than 10 dollars.
这件T恤少于10美元。
Fewer than half the students pass the test.
少于一半的学生通过了考试。

fewer + 可数名词复数 + than 比…少…
I have fewer books than you.
我有的书比你的少。
They have fewer toys than you.
他们有的玩具比你们少。

2.few的最高级fewest，用于三者及以上比较
My class has the fewest students.
我的班级有最少的学生。
He has the fewest books.
他有最少的书。
I have the fewest toys in my family.
在我家，我有最少的玩具。