Letter Perfect Answer

Without knowing the story behind this puzzle, I think it is pretty difficult. So I’ll explain.

To review — I said these letters share a unique characteristic:

c
g
q
w
y

Any guesses?

The explanation: During a word game [Scrabble maybe -- not that it matters really] someone played a word like “ess” [although it easily could have been any of several others besides ess -- again, not that it matters]. “Ess” may refer to anything that is shaped liked the letter S but it also refers to the actual letter S and to the way the letter S is pronounced. One of my nephews objected that spelling the pronunciation of the letter S using the letter S is the same as using a word in the definition of itself [which we have all been taught not to do].

While I understand his point, it got me thinking that most letters are used in spelling how to pronounce themselves. In fact, there are several letters I can’t think of any way not to use the letter in pronouncing itself. [Can you think how to describe the pronunciation of "B," for example, without using "B" in pronouncing it? We only get the "B" sound with a "B"....] So I decided to look them all up. [Using a different authority might provide slightly different results, but I rather doubt it.]

I used the Merriam-Webster Online Dictionary just because that’s the one I use most often. According to that source, these are the only five letters for which spelling the pronunciation does not include the letter itself:

c = ˈsē
g = ˈjē
q = ˈkyü
w = ˈdə-bəl-(ˌ)yü, ˈdə-bə-; ˈdəb-(ˌ)yü, -yə; ˈdəb-yē
y = ˈwī