Proper application of the alphabetic principle rests on an awareness of the internal phonological (and morphophonological) structure of words that the alphabet represents. Unfortunately for the would-be reader-writer, such awareness is not an automatic consequence of speaking a language, because the biological specialization for speech manages the production and perception of these structures below the level of consciousness. Not surprisingly, then, awareness of phonological structures is normally lacking in preliterate children and adults; the degree to which it does exist is the best single predictor of success in learning to read; lack of awareness usually yields to appropriate instruction; and such instruction makes for better readers. That some children have particular difficulty in developing phonological awareness (and in learning to read) is apparently to be attributed to a general deficiency in the phonological component of their natural capacity for language. Thus, these children are also relatively poor in short-term memory for verbal information, in perceiving speech in noise, in producing complex speech patterns, and in finding the words that name objects. All children will benefit from instruction that is intelligently designed to show them what the alphabet is about. (Contains a figure and 81 references.) (Author/SR)