Theoretical Grammar The subject-matter of theoretical grammar. Its relation to practical grammar

Articulatery and physiological classification of E vowels. According to the stability of articulation.
The stability of articulation is the principle of vow classification which is not singled out by British and American phoneticians. It is the principle of the stability of the shape, volume and the size of the mouth resonator. According to this principle v are subdivided into:
1.monophtongs-simple v
2.diftongs-complex v
1)English mon-gs are pronounced with or less stable lip, tongue, mouth walls position. They are [ I: i e эе a: o 3: u u: Λ o: ə ].
2)Definition of a diphthong as a single-sound is based on the instability of the second element. The first element of a diphthongs is the nuclear, the second is the glide. A diphthong can be falling, when the nucleous is stronger than the glide, and rising, when the glide is stronger than the nucleous. When both elements are equal such diphthongs are called level. Eng. Diph-s are falling with the glide towards:[i]-[ei ai oi]
Dif-s [ei eu oi ai au]-are called closing dif-s, dif-s[3e ie ue]-are called centring, acoording to the articulation of the 2 element.
There are 2 v in English[I: u:] that may have a diphthongal glide where they have full-length (in open syllables) and before lenis or nasal cons (bi:-bi:d-bi:n.). Russian v [э о] are diphtongoids.

2. 
   The articulatory classification of the English consonants. (Класифікація приголосних англійської мови за артикуляцією.)
   

Articulatory and physiological classification of English consonants. Accord to the work of the vocal cords and the force of exhalation, active organs of speech and the place of abstraction.
Rus phenetitians classify con-s according to the following principles:
1work of the vocal cords and the force of exhalation
2active organs of speech and the place of obstruction
1. Accoring to the work of the vocal cords and the force of exhalation cons-s are subdevided into voiced and voiceless. Voiced: [b, d, g]; voiceless: [p, t, k,]. The force of exhalation and the degree of muscular tension are greater in the production of voiceless cons-s. Therefore they are called by the Latin word fortis, which means strong, energetic. Voiced cons-s are called lenis, which means soft, weak. Because the force of exhalation and the degree of muscular tension in their articulation are weaker, e.g.fortis: [p] – pipe, [t] – tight, Lenis: [b] – Bible, [d] – died.
The Eng cons-s [h, m, n, h, l, w, j, r] don’t enter into fortis-lenis oppositions.