Abstract: A spelling error detector apparatus employs a memory which stores alphabetical words as those existing in the English language in three major memory sections which constitutes a most frequently used word list (MFU), a master word list (MWL) and a personal word list (PWL). Each word is uniquely coded and stored as a 24 bit binary number. The system then retrieves words which are stored or entered into a processor memory and which words are indicative of a document to be printed. Each word emanating from the processor memory is converted into the same code as the stored words and then a search is made to determine whether the processor word compares with a word as stored. If a favorable comparison is had, it is assumed that the spelling of the processor word is correct. If an unfavorable comparison is had, it is assumed that the spelling is incorrect and the misspelled word is stored in a separate memory which can be accessed by the operator in order to make the necessary corrections.