This word riddle sounds impossible at first. Normally, adding letters makes a word longer, not shorter. But the question is playing with the meaning of the finished word rather than its physical length.
Start with the word “short.” Add the two letters “e” and “r” to the end, and you get “shorter.”
Answer: Short.
“Short” becomes “shorter” when you add two letters to it. Of course, the new word contains more letters, but its meaning is exactly what the riddle asks for.
This is a classic example of a wordplay puzzle where taking the wording literally in one sense leads you away from the simple answer.
