The most commonly used letter in the English language is E.
In typical English writing, E accounts for roughly 12–13% of all letters, though the exact figure changes with the sample. Newspapers, novels, technical documents, dictionaries, and online text can each produce slightly different rankings. T is usually the most common consonant, while A, O, I, and N also appear frequently.
E’s high frequency comes from its role in many common grammatical endings and function words. It appears in words such as “the,” “be,” “he,” “she,” “we,” and “were,” and in endings including “-ed,” “-er,” and “-est.” The silent E also helps distinguish word forms and pronunciation, as in “rid” and “ride.”
Letter frequency is especially important in cryptography. In a simple substitution cipher, the most frequent symbol often represents E, giving codebreakers a useful starting clue. A common mix-up is to confuse the most frequent letter overall with the most common first letter of English words; those rankings are different, and E is not always first in that comparison.