The Prague and London Phonological schools. Phonological trends in the USA and other countries The plan: 1. The Prague phonological school 2. Trubetskoy’s phonological ideas II. The London phonological school 1. The representatives and the main concept of the school 2. D. Jones’s ideas.I II. Phonological trends in the USA 1. Bloomfieldian descriptive phonology 2. American tagmemic school 3. Generative-transformational phonology 4. The Copenhagen Phonological school His pupil and disciple L.V. Shcherba, who took the phoneme theory a stage further, was naturally under the influence of his teacher's views and the Leningrad Phonological School's theory is closely connected with the name of academician L.V. Shcherba. His followers and pupils L.R.Zinder, Y.S.Mastow, M.I. Matusevitch, L.V.Bondarko, V.I.Litkin and O.l.Dickushina were representatives of this school. Much attention should be paid to the variants of the phonemes (allophones), to their linguistic (social) aspects and phoneme combinations. The Leningrad Phonological school's definition of a phoneme is based on words and word forms, i.e. the phoneme is considered to be the smallest unit capable of differentiating words and word forms. The representatives of this school based their definition of a phoneme on the concept of the morpheme. Analyzing the sound changes in the morphemic structure of a language, it is possible to establish 2 different positions: stressed and unstressed. In a stressed position phonemes can preserve their phonetic characteristics, while in an unstressed position they change their articulator and acoustic features - they distinguish "weak" and "strong" positions. This fact is very important in the phonetic analysis of Russian vowels.A great number of linguistics has written on the subject of phonemes and many linguistic schools of thought appeared in many countries. The London school of phonology