Q: Think of a common five-letter word in one syllable. Change the fourth letter to the next letter of the alphabet, and you'll get a common word in two syllables, also in five letters. What words are these?6, 2, 7, 6D --> 8, 9, 11, 29D
Edit: Since Will Shortz is the editor of the New York Times crossword puzzle, my hints are to those puzzles. On 6/2/2007 the clue for 6 down was Charm (Ans: ENDEAR) and on 8/9/2011 the clue for 29 down was Chasm (Ans: ABYSS).
A: CHARM --> CHASM