Content Introduction.......................................................................................................... 1 The investigation of the phoneme as a language unit I.1 The phoneme as a unity of three aspects.................................................... I.2 The conceptions of the phoneme…………………………………………. I.3 The system of English phonemes........................................................... I.3.1 The system of vowel phonemes...................................................... I.3.2 The system of consonant phonemes................................................. I.4 Main trends in the Phoneme theory. .......................................................... I.5 Methods of Phonological analysis......................................................... I.6 Phonological schools............................................................................. I.7 Phoneme and allophone......................................................................... Chapter II. Practical part Comparative analysis of characteristic features of sound system of English and Russian language................................................................................................. Conclusion....................................................................................................... Bibliography.....................................................................................................