What do the following words have in common that has nothing to do with their meanings?

 

1. FED

2. MEN

3. SPINE

4. PAPER

5. PURSE

 

HINT:

The same letter will change each word into a new one:

 

Answer:

 

Each word becomes a new one with the addition of the letter U somewhere in the word:

 

1. FEUD

2. MENU

3. SUPINE

4. PAUPER

5. PURSUE

 

Credit:

Ben Hamilton