The British phonetician Daniel Jones said: "We think in phonemes and speak in allophones". So in speech all the phonemes are manifested in their allophones.

ALLOPHONES of a certain phoneme are speech sounds which are realizations of one and the same phoneme and which can't distinguish words.

Allophones can be:

1. POSITIONAL - are used in certain positions traditionally; can be dialectal or individual.

2. COMBINATORY - appear in the result of assimilations, adaptation, accomodation - 1 sound is influenced by another.

Allophones of the same phoneme, no matter how different their articulation may be, function as the same linguistic unit. Phonemes differentiate words like "tie" and "die" from each other, and to be able to hear and produce phonemic differences is a part of what it means to be a competent speaker of the language. Allophones, on the other hand, have no such function: they usually occur in different ostions in the word (i.e. in different environments) and hence can't be opposed to each other to make meaningful distinctions.

Methods of the identification of phonemes in a language

The 1st problem of phonological analysis is to establish the number and system of phonemes in the language. There are 2 methods of analysis:

1. DISTRIBUTIONAL METHOD - states that the sounds can be groups of phonemes (allophones of 1 phoneme occur only in different context because they can't perform distinctive function). It is purely formal method of identifying the phonemes of a language.

2. SEMANTIC METHOD - is based on the phonological rule that a phoneme can distinguish words (the meaning or the form) when it is opposed to another phoneme in identical phonetic contexts (so-called minimal pairs).

The distinctive and non-distinctive features of English vowels

Vowels have 2 main characteristics: length and quality. Quality is the distinctive feature of a vowel, regardless of the position of the vowel. It components:

1. stability of articulation (monophthongs, diphthongs, triphthongs, diphthongized vowels)

2. the position of the tongue (horizontal and vertical movement of the tongue, lip rounding)

Other components are:

1) lip position

2) tenseness

3) checkness

They are considered non-distinctive as they have no phonological value. Vowel LENGTH also a non-distinctive feature. It is dependent on the phonetic context, in the particular on the following consonant. It is the so-called "positional length". Vowels are the longest in the open syllable, slightly shorter before a sonorant or a voiced consonant and they are the shortest before the voiceless consonant:

be [i:] - the longest

beed [i:d] - a bit shorter

beat [i:t] - much shorter

The distinctive and non-distinctive features of English consonants

Most phoneticians agree that distinctive features of English consonants are:

1. manner of articulation way in which the obstruction of the airstream is produced - Vasiliev's point of view (occlusives – 2 articulators form a complete closure which is suddenly released, constrictives – the 2 articulators come close together forming a stricture, affricates)

2. place of articulation – the location in the vocal tract where a particular speech sound is produced (labial:bilabial/labio-dental, lingual:dental/interdental/alveolar/palato-alveolar/post-alveolar, glottal)

3. degree of noise - Sokolova's point of view (noise, sonorants)

The following characteristics are not important from the phonological point of view but still very important for the articulation of sounds:

1) palatalization – softening of the consonants due to the rising of the back of the tongue to the hard palate

2) aspiration – puff of air following the release of a plosive

3) nasalization- pronounce or utter (a speech sound) with the breath resonating in the nose