Words by length
| 1 letter | A, I |
|---|---|
| 2 letters | OF, TO, IN, IT, IS, BE, AS, AT, SO, WE, HE, BY, OR, ON, DO, IF, ME, MY, UP, AN, GO, NO, US, AM |
| 3 letters | THE, AND, FOR, ARE, BUT, NOT, YOU, ALL, ANY, CAN, HAD, HER, WAS, ONE, OUR, OUT, HAS, HIS, HOW, MAN, NEW, NOW, OLD, SEE, WHO, ITS |
| 4 letters | THAT, WITH, HAVE, THIS, WILL, YOUR, FROM, THEY, BEEN, WERE, WHAT, WHEN, THEM, THAN, SOME |
Patterns help more than lists. A four-letter word whose first and last letters match is often THAT. Two three-letter code words that share their last two letters may be THE and SHE. After an apostrophe, one letter is usually S or T; two letters are often LL, RE or VE.
Letter frequency
In ordinary English text, about one letter in eight is E. The rough order of the most common letters is E T A O I N S H R, and the rarest are J X Q Z. In a short quote the counts are noisy, so use them to rank guesses, not to decide them.
Worked on puzzle 1: the most common code letter is R, 10 times. Rather than call it E, check the words first: the quote is full of two-letter words, and DR, DN, CQ and JQR repeat. Short-word patterns beat letter counts here.
Questions people ask
What is the most common word in a cryptogram?
THE, by a wide margin, then AND, OF, TO and A. A three-letter code word that repeats is THE more often than not.
What is the most common letter?
E, at about one letter in eight in ordinary English, then T and A.
What are the most common double letters?
LL, EE, SS, OO and TT.
Can a letter stand for itself?
Not in a standard cryptogram: a code letter always means a different letter.