1. Phoneme theory, Prague Structuralism.

One of the founders of the Prague school N.S. Trubetzkoy: phonemes — sets of distinctive features. Phoneme as a cluster of DFs is discrete and invariant, but its realization may vary.

Systemizing phonological oppositions, based upon such features.

N.Trubetzkoy put forward three criteria for classifying phonological oppositions:

1. their relationship with the other oppositions of the same system;

2. the relationship between the members of the same opposition;

3. the extent of their distinctive force in different positions.

According to these criteria the following types of oppositions were distinguished:

1. bilateral and multilateral oppositions;

2. privative, gradual and equipollent oppositions;

3. constant and neutralizable oppositions.

Thus according to N.Trubetzkoy phonemes are "phonological units which from the point of view of a particular language are further indivisible into smaller consecutive segments".

Each phoneme is to be a member of some phonological opposition. It means that the phoneme is identical not with a particular sound but it is identified as a cluster of phonologically relevant features of a sound.

Trubetzkoy's most prominent monograph "Principles of Phonology" was published in 1939 (in the German language).

2. Jacobson:

The phoneme is a set of DF

They are opposed by one or more sound features. It may be expressed in articulatory or in acoustic terms.

Phonemes are discreet and invariant, but realization may vary.

Jacobson presented the idea of binarism as the most important relationship between linguistic units.

He has also invented the inventory of DFs (12): the generalized some articulatory and acoustic features. According to this classification, all phonemes may be:

• (non) consonantal

• (non) vocalic

• (non) nasal

So all the phonemes can be grouped: vowels (v, nc), consonants (nv, c), liquids l, r (v, c), glides j, w (nv, nc)

Advantages of the DF:

• universal (all possible oppositions in all alnguages)

• all features are binary in nature

• these features can be defined in acoustic terms

3. Phoneme theory: American Structuralism.

American structuralists (or descriptivists): abstractional view of the phoneme or a phenomenon very similar to sound. Thus one can speak of several approaches to the problem of phoneme in this trend of linguistics.

L.Bloomfield: phoneme as a bunch (or cluster) of distinctive features.

W.F.Twaddel: fictionalist view of the phoneme: "an abstractional, fictitious unit", "a scientific fiction".

B.Bloch, Ch.Hockett, Z.Harris define the phoneme as a class of phonetically similar sounds, contrasting and mutually exclusive with all similar classes in the language. The generalized character of the phoneme is denied by these linguists, the phoneme is presented as a mechanical sum of its allophones.

According to V.A.Vassilyev, the linguists who deny the distinctive function of the phoneme and define it as the sum total of its mutually exclusive allophones have to object to the use of the semantic method of phonological analysis: in their opinion it is possible "to group the sounds of a language into phonemes even without knowing the meaning of words" as D. Jones would say [Vassilyev 1970: 160].

This belief is based on two laws of phonemic and allophonic distribution:

1. Allophones of different phonemes always occur in the same phonetic context (otherwise the phonemes could not fulfill their distinctive function);

2. Consequently, the allophones of the same phoneme (with the exception of its free variants) never occur in the same phonetic context and always occur in different positions, which determine the articulatory and acoustic differences between the variants of one and the same phoneme.

Two conclusions come from these laws:

1. If more or less different speech sounds occur in the same phonetic context, they should be allophones of different phonemes (= contrastive distribution);

2. If more or less similar speech sounds occur in different positions and never occur in the same phonetic context, they are variants of one and the same phoneme (=complementary distribution).

Thus the phonemic status of a sound can be established "even without knowing the meaning of words", i.e. only on the basis of the distribution of sounds in it. This is the purely distributional method of identifying phonemes.