General principles of the classification of English vowel and consonant phonemes. English vowels are classified according to the following principles: 1. Position of the lips. 2. Position of the tongue. 3. Length. 4. Degree of tenseness 5. The character of the end. 6. Stability of articulation.

1. According to the position of the lips vowels are divided into rounded [o, o:, u, u:] and unrounded – all the rest. The main effects of lip rounding on the shape of the mouth are to enlarge the oral cavity, to diminish the size of the opening of the oral cavity.

2. Vowels are classified according to the horizontal and vertical movement of the tongue. According to the horizontal movement of the tongue English vowels are divided into front, front-retracted, central, back and back-advanced. Front vowels are articulated when the bulk of the tongue moves forward and its front part is raised highest towards the hard palate. They are [i:, e, æ]. Front-retracted vowels are articulated with the front but a bit retracted position of the tongue. It is [i]. Central vowels are articulated with the tongue almost flat and its central part raised to the juncture between the hard and soft palate. They are [з:, ə, Λ]. Back vowels are articulated when the bulk of the tongue moves backward in the mouth cavity and its back part is raised highest to the soft palate. They are [o, o:, u:]. Back-advanced vowels are articulated with the back but a bit advanced position of the tongue. The are [u, α:]. According to the vertical movement of the tongue English vowels are divided into high (close), mid and low (open). Each of these classes is subdivided into narrow and broad subtypes. High vowels are articulated with the bulk of the tongue raised high to the roof of the mouth, but not so high as to produce an audible friction. In pronouncing high narrow vowels [i:, u:] the bulk of the tongue is raised higher than in pronouncing high broad ones [i, u]. Mid vowels are articulated with neither high nor low position of the tongue that is why they are also called half-close or half-open. Mid narrow vowel is [ ə ], mid broad vowels are [e, o:, з:]. Low vowels are articulated with the bulk of the tongue in the low position in the mouth. In pronouncing low broad vowels [æ, α:, o:] the bulk of the tongue is lowered more than in pronouncing low narrow vowel [Λ].

3. According to the length English vowels are divided into long [i:, u:, o:, α:, з:] and short [i, u, o, æ, e, ə, Λ].

4. According to the degree of tenseness English vowels are divided into tense and lax. Tense vowels are articulated when the muscles of the lips, tongue, cheeks and the back walls of the pharynx are tense. Lax vowels are articulated with all these organs relatively relaxed. All long vowels are tense while all short vowels are lax.

5. English vowels in stressed position can be checked and unchecked (free). The checked vowels are pronounced without any lessening of the force of utterance towards the end. They occur in close syllables and are abruptly interrupted by the following voiceless consonant. The unchecked vowels occur terminally or before a voiced consonant. The vowel [ ə ] does not occur in the stressed position so it is not regarded inside these classes.

6. According to the stability of articulation English vowels are divided into monophthongs, or simple vowels and diphthongs, or complex vowels. Monophthongs are articulated with more or less stable lip, tongue and walls position. They are [i, i:, u, u:, o, o:, e, ə, Λ, α:, æ, з:]. Diphthongs are articulated in such a way that organs of speech start from one position and then glide to another position. So diphthongs consist of two elements: a nucleus and a glide. The first element of a diphthong is more loud and distinct, the formation of the second element of a diphthong is not accomplished. They are [ai, oi, ei, au, ə u, ε ə, u ə, i ə ]. Diphthongs are unisyllabic, that is its parts can not belong to different syllables. Their length should not exceed the length of a single phoneme. They can not be divided morphologically. There is an opinion that one element of a diphthong is accented while the other is not. A diphthong may be falling – when the nucleus is stronger than a glide, rising – when the glide is stronger than a nucleus, and level – when both elements are equal. English diphthongs are falling with the glide toward [i, u, ə ]. According to the articulatory character of the second element, diphthongs [ai, oi, ei, au, ə u] are called closing, while diphthongs [ε ə, u ə, i ə ] are called centring.

English consonants are classified according to the following principles: 1. Work of the vocal cords and the force of exhalation. 2. Active organ of speech and the place of obstruction 3. Manner of the noise production and the type of obstruction. 4. Position of the soft palate.

1. According to the work of the vocal cords and the force of exhalation English consonants are subdivided into voiced and voiceless. Voiced consonants are produced with the vocal cords brought together and vibrating. They are [b, d, g, v, z, ð,3, d3, l, m, n, j, w, r, ŋ]. Voiceless consonants are produced with the vocal cords taken apart and not vibrating. They are [p, t, k, f, s, θ,, t, h]. The force of exhalation and the degree of muscular tension are greater in the production of voiceless consonants.

2. According to the position of the active organ of speech against the place of obstruction English consonants are classified into labial, lingual and glottal. Labial consonants are subdivided into bilabial and labiodental. Bilabial consonants are articulated with both lips. They are [p, b, w, m]. Labiodental consonants are articulated with the lower lip against the edge of the upper teeth. They are [f, v].

3. According to the type of obstruction consonants are divided into occlusive, constrictive and occlusive-constrictive or affricates. Occlusive consonants are articulated with the air on its way out breaking up a complete obstruction. In English occlusive consonants are subdivided into plosives [p, t, k, b, d, g] which are articulated with distinct and quick separation of the obstruction and sonorants [m, n, ŋ]. Constrictive consonants are articulated with incomplete obstruction through which the air comes out. In English constrictive consonants are subdivided into fricatives [s, f, z, ð, θ,, v,3, h] which are articulated with the air passage narrowed to such an extent that the air passing through it produces friction, and sonorants [w, r, j, l] which are articulated with the air passage wide enough to make the cavity function as a resonator. Occlusive-constrictive consonants are articulated with the complete obstruction gradually and uninterruptedly opening into narrowing. In English they are [t, d3].

4. According to the position of the soft palate consonants are subdivided into oral and nasal. Nasal consonants are articulated with the blocked passage for the flow of air through the mouth cavity which is effected by lowering of the soft palate. They are [m, n, ŋ]. All the rest consonants are oral. Oral consonants are articulated with the raised soft-palate, thus the air goes out through the mouth cavity.