The author discusses "the parallels between learning English as a foreign language and learning English as a native language and their relevance for the construction of appropriate teaching materials." Four postulates or language universals are presented about the order in which children learn the phonological features of their native language (after Jakobson). The author concludes that "certain phonemes are either more easily perceived visually or acoustically or...are more easily reproduced physiologically." The textbook writer, therefore, should grade English (or other foreign language) teaching materials to reflect this natural order of difficulty. (JD)