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.
  • LetterQ treats as letters all special characters explicitly listed as letters in the table in "Named 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 α, , , and æ.
  • LetterQ does not treat as letters (\[EmptySet]), (\[HBar]), (\[Angstrom]), or (\[Sum]).
Introduced in 1991
| Updated in 1996