The following words can be changed into different ones by the addition of a single letter. The solution is not unique, but if you choose five particular letters, and place them in a certain way, the words will form an unmistakable pattern.

MOUNT

RIGHT

LEFT

EAR

MERGE

HINT:

The first letter is A.

Answers:

AMOUNT

BRIGHT

CLEFT

DEAR

EMERGE (Initial letters in ABC order)