I suspect if we taught preschoolers to speak many would not learn nearly as well as they do in their own independent manner. The very young child learns to speak when he wants to, in the way he wants to, because he wants to. Above all else, he does not become anxious about what he can not understand or can not do. He does not worry about making mistakes. He does not worry about being wrong. He does not fear an extrinsic evaluation of his progress. He meets only success.
Wright, J. A. (1969). Another Declaration of Independence. Reading Horizons: A Journal of Literacy and Language Arts, 9 (3). Retrieved from https://scholarworks.wmich.edu/reading_horizons/vol9/iss3/6