Language patterns are the biggest clues for code crackers.
On this site I focus on the English language.
Most common letters: E, T, A, O, I, N, S, H, R
Most common starting letters: T, O, A, W, B, C, D, S, F, R
Most common finishing letters: E, S, T, D, N, R, Y, F, L, O
To find out about digraphs, for Playfair perhaps, click below.
The most commonly used words in written English are: