This is documentation for Mathematica 6, which was
based on an earlier version of the Wolfram Language.
View current documentation (Version 11.2)


yields True if all the characters in the string are letters, and yields False otherwise.
  • LetterQ[string] by default gives False if string contains any space or punctuation characters.
  • LetterQ handles both ordinary and special characters.
  • In general, LetterQ treats as letters all characters that appear as ordinary text in any language.
  • LetterQ treats as letters such special characters as , , and æ.
New in 2 | Last modified in 3