I Know A Word Of Letters Three, Add Two And Fewer There Will Be?

Riddle: I know a word of letters three, add two and fewer there will be?

Answer: The word "few". Add "er" and it becomes fewer.

Source: https://www.riddles.com/1068

I know a word of letters three, add two and fewer there will be? — I know a word of letters three, add two and fewer there will be? by Anonymous v1.

Riddle: I know a word of letters three, add two and fewer there will be? Answer: The word "few". Add "er" and it becomes fewer. — by Anonymous v2.