A knowledge of transformational grammar may shed considerable light on a wide variety of ready "lapses." A skillful teacher who understands the origin of these errors may deal with them more effectively than in the past. This thesis is based on the quite widely accepted hypothesis that the grammar of the language has rules which operate in a certain order to produce or account for the sequence of forms underlying English grammatical sentences. Assumed is some correspondence between the rules and whatever neurological processes go on as the speaker speaks, the hearer hears, or the oral reader performs something of both of these processes. Modern linguistic study has confirmed something in the two main approaches to reading--"phonics" and "look-say." Suggested here is the notion of a larger "look-think-reproduce" theory, in which the "look" is not at a word, but at a total linguistic structure, the "think" is a grammatical decoding of the symbols seen in the "look," and the "reproduce" is a speech act based on generative performance that the reader gives following that grammatical decoding. Presented in this paper are data from a preliminary study of reading errors which tend to confirm that the process of reading is not solely, or even primarily, a question of identifying words, or translating graphic symbols to phonetic instructions. Even at a very early grade level, the whole grammatical process is involved. (AMM)