Category Archives: letter frequencies in English

1. What is the most frequently used vowel in text?
2. What is the least frequently used vowel?
3. What is the most frequently used consonant?
4. What is the least frequently used consonant?

And the answers are

1. E is the most frequently used vowel.
2. U is the least frequently used vowel.
3. T is the most frequently used consonant.
4. Z is the least frequently used consonant.

How did you go about figuring out your answer?  I thought of  letter frequencies in the game Scrabble.  I know from playing the game that E has the most tiles of any letter–12 tiles.  A and I have nine tiles, O has 8, and U has 4.

For consonants, I was stumped.  Again, I thought of Scrabble tiles.  I chose S, but S has only four tiles.  N and T both have six.  In fact, T is the most commonly used consonant.  For the least commonly used consonant, I would have chosen Z or Q or X based on the number of Scrabble tiles and also on the value of those tiles (each worth 10 points).

Who cares?  If you are someone who deciphers coded messages, knowing expected letter frequency can help.  Almost two hundred years ago, Samuel Morse, the inventor of Morse Code, needed to know which letters were more commonly used in order to assign them the simplest dot and dash patterns.  He didn’t have Scrabble to help him.  He turned to sets of letters printers used.

Morse found that the letter E appeared 12,000 times, the letter T 9,000 times, the letter U 3,400 times, and the letter Z 200 times in printers’ job cases. These numbers relate to the number of times letters are used in commonly used English words, not to the number of times they appear in a collection of all English words.

To find how many times letters appear in all English words, the number of letters in every word in the Concise English Dictionary (1995) was computed.  Those results show the letter E is used the most, followed in descending order by A, R, O, I, T, N, and S.  U appears least of all the vowels, and Q appears least of all the consonants.

If you wonder about the frequency of letters appearing at the beginning of words, S is the clear-cut winner.  E appears halfway down the list, and X is the least used first letter in English.

Writing topics yield different letter frequencies.  For example, most fiction is written in the past tense, increasing the expected number of times D and ED appears.

The California Job Case was a box used to sort and store moveable type. The number of times a letter appears in the box is shown by the relative size of the compartment allotted to that letter.