The addition of a  single letter to each clue below will change the words into new ones which all have something in common. The added letter is different for each word.

1. FLIT
2. CAPER
3. DOVE
4. SALE
5. BUTT

Answers:

1. FLIT + N = FLINT
2. CAPER + S = CASPER
3. DOVE + R + DOVER
4. SALE + M = SALEM
5. BUTT + E = BUTTE 

Credit: Will Shortz
NPR Weekend Edition Sunday Puzzle
Nov. 29, 2008
CITY SLICKERS