The strings of letters in each clue below can be separated into familiar two-word phrases by making the same change to each letter string. What is the change and what are the phrases?

1. FILUT
2. DIOKE
3. SECRODE
4. MUPPAPER
5. INTERNHAT
6. MARKRASH
7. SWEHARITY
8. CHEVROLORVETTE

Answers:

The letters ETC can be inserted somewhere into each letter string to make familiar two-word phrases:

1. FILET CUT
2. DIET COKE 
3. SECRET CODE 
4. MUPPET CAPER 
5. INTERNET CHAT 
6. MARKET CRASH
7. SWEET CHARITY 
8. CHEVROLET CORVETTE 

Credit: 
Robert W.  Harris
AND SO ON