A study investigated the reading responses of 60 eighth grade students to encoded inflectional, syntactic, grammatical, and semantic errors. The students were equally divided into three categories based on grade level reading competency and given three Aesopian fables to read. The text of the fables contained the following errors: (1) words to which inflectional and derivational suffixes had been added or deleted, (2) substitutions of one structure word for another, (3) substitution of antonyms for synonyms, and (4) substitution of the word "kelp" for the verb "keep." Each student read the fables orally and as rapidly as possible without knowing that errors had been inserted in the materials. The readings were recorded and analyzed to determine how each student responded to the errors. The overall performance of the students indicated that they were not overly sensitive to encoded errors. They were more proficient in intuitively correcting inserted errors that violated past tense, with regular past tense errors being corrected more frequently than irregular past tenses. They were least proficient in correcting inserted antonyms for synonyms, indicating that the students were less semantically aware than syntactically and grammatically aware. (FL)