User:Кривелева Анастасия/sandbox

Vowels
In phonetic materials, the noun "vowel" has the following meanings: a vowel sound; a letter representing a vowel sound in writing. Vowels are speech sounds produced without obstructing the flow of air from the lungs, so that the breath stream passes freely through the mouth. Vowels are always voiced (i.e., the vocal cords vibrate). Syllables are formed by vowels: I [ai], me [mi:], my [mai], so [sou], lid [lid], let [let], late [leit], lord [lo:rd].

There are six vowel letters in the English alphabet: a, e, i, o, u, y. Or five, if Y is regarded as a consonant. The letter Y can represent a consonant / semivowel (yes, yard) or a vowel (mystery, try, play). Vowel letters, alone or in combinations, represent from 15 to 22 vowel sounds, depending on the way of counting. All vowel sounds together are called the vowel system.

Vowel sounds are divided into:
 * 1) monophthongs
 * 2) diphthongs
 * 3) triphthongs

Monophthongs
A monophthong consists of only one vowel sound that does not change during its articulation; i.e., it starts and ends in the same quality, and the speech organs do not change their position during its pronunciation. Monophthongs are also called simple vowels, pure vowels, or stable vowels. American linguists list from 9 to 12 monophthongs in American English, generally 11 monophthongs:
 * [a:]
 * [æ]
 * [i:]
 * [i]
 * [e]
 * [o:]
 * [o]
 * [u:]
 * [u]
 * [ər]
 * [ə]

Diphthongs
A diphthong is a complex vowel sound that consists of two components. The first part of the diphthong is its main strong component (the nucleus); the second part is short and weak (the glide). Together, the nucleus and the glide form one vowel sound that is indivisible and forms only one syllable. Examples of one-syllable words in which there is only one vowel sound, i.e., the diphthong: [ai] ride, right, lie, buy; [au] brown, cloud; [ei] late, pray, pain, straight; [oi] toy, spoil; [ou] go, toe, phone, road, bowl, though. A diphthong is always stressed on its first main component.

Triphthongs
A triphthong is a complex vowel sound that consists of three components. A triphthong is indivisible and forms only one syllable. A triphthong is always stressed on its first main component. Two triphthongs are usually listed in British English: [aiə] hire, fire, require; [auə] our, hour, flour. American linguists generally do not list triphthongs because the neutral sound (i.e., the third component of these triphthongs) is often lost before voiced [r] in AmE, for example, fire [fair], [fai(ə)r]; flour [flaur], [flau(ə)r]. In other cases with [aiə], [auə], these sounds are regarded as two separate vowels in two adjoining syllables, for example, di-al, qui-et, high-er; tow-el, flow-er, tow-er.