The functions of listening, speaking, reading, and writing, should form a solid foundation from which students can learn as they grow toward maturity in their educational endeavors. Without a proper grasp of those functions, a language imbalance occurs. One might say that the foundation tilts because the base is not sufficiently solid in each direction. As a result one or more language functions are slighted and may not mature sufficiently or may atrophy because of disuse.
Lloyd, B. A. (1976). Reading to Write. Reading Horizons: A Journal of Literacy and Language Arts, 16 (4). Retrieved from https://scholarworks.wmich.edu/reading_horizons/vol16/iss4/8