What is the frequency of the letters of the alphabet in English?
The inventor of Morse code, Samuel Morse (1791-1872), needed to know this so that he could give the simplest codes to the most frequently used letters. He did it simply by counting the number of letters in sets of printers' type. The figures he came up with were:
|8,000||A, I, N, O, S||1,700||G, P|
However, this gives the frequency of letters in English text, which is dominated by a relatively small number of common words. For word games, it is often the frequency of letters in English vocabulary, regardless of word frequency, which is of more interest. We did an analysis of the letters occurring in the words listed in the main entries of the Concise Oxford Dictionary (11th edition revised, 2004) and came up with the following table:
The third column represents proportions, taking the least common letter (q) as equal to 1. The letter E is over 56 times more common than Q in forming individual English words.
The frequency of letters at the beginnings of words is different again. There are more English words beginning with the letter 's' than with any other letter. (This is mainly because clusters such as 'sc', 'sh', 'sp', and 'st' act almost like independent letters.) The letter 'e' only comes about halfway down the order, and the letter 'x' unsurprisingly comes last.