English orthography, or the manner in which we employ the alphabet to suggest words' phonetic expressions, is notoriously irregular. It presents a full continuum from the straightforward, like mat, to the indirect but regular, like bubble, to the quite bizarre, such as phlegm. This illogical relationship adds a level to the already-present difficulty that means only the truly savvy ever really master English. It has afforded me many opportunities for witty discussion and happy contemplation.

A recent such contemplation reminded me of a favourite word of mine, told to me by my Grade 7 teacher, namely bookkeeper, which contains no less than three consecutive double letters. I then proceeded to puzzle over the presence of double letters within words.

My immediate gut reaction was that certain letters wouldn't occur as doubles, but, being of an inquiring mind, I considered this stance in further detail. I soon came to see that, as a matter of fact, most letters are doubled quite regularly. Some, of course, are found only in unusual words like aardvark, skiing, withhold or yellowwood. There are, as far as I can tell, a mere four that don't ever appear as doubles: J, Q, X and Y. The rest all appear - this post is proof.