The words below, when the same two letters are added to them, can be re-arranged to form new words. The two added letters remain in the same, consecutive order in the new words.

1. NAYS
2. LIES
3. LIFE
4. RUBE

Answers:

The added letters are ZZ, and the new words are:

1. SNAZZY
2. SIZZLE
3. FIZZLE
4. BUZZER