Theoretical and applied aspects of sublanguage study belong to one of the most promising trends in modern linguistics. Special lexical means, i.e. terms, have always been the basis for defining the essence and specificity of sublanguage. As a result, the majority of sublanguage studies center on the lexical system of sublanguage, to be more exact, its terminological layer. However, functional studies of sublanguage can by no means rely on the traditional notion of sublanguage as a terminological system. To define the nature of sublanguage in the light of anthropocentric approach to language study, we must turn to its functioning in communication, i.e. in communicative acts.

Communicative act (CA) is the basic unit of communication, its integral functional fragment of communicative interaction. In order to get a better understanding of CA and to carry out certain applied tasks, the method of modeling is used. A model of communicative act (CA-model) represents its constituent elements and functional characteristics in the schematic form. It is important to understand that every CA-model is developed to solve certain theoretical and practical problems and can be effectively used only in a limited area of application. Such classical CA-models as the teleologic model of R. Jacobson, the transmission model of C. Shannon and W. Weaver, the inferential model of P. Grice, as well as many others don’t cover or don’t put in the center of attention those aspects of CA that are necessary to reveal the essence and specificity of sublanguage. Sublanguage serves this or that sphere of professional communication (SPC). And the model should include psychological, social and pragmatic parameters of CA that would be sufficient enough to determine characteristic features of CAs, common for all SPC. Defining the nature of sublanguage, we shall lean on the model of verbal communicative act by B. Gorodetsky, which, we believe, suits our task best of all. It consists of five basic components: 1. communicants; 2. circumstances of communication; 3. system of communicative intentions; 4. communicative processes; 5. communicative text.

Speaking about communicative aspects of sublanguage, we turn to the notion of professional communicative act (PCA), which is the basic unit of professional communication. So let’s have a look at each component of CA in its ‘professional perspective’.

1. Communicants.

There are three main cases here. 1. Communicants are specialists in the same area of knowledge. This is the specialist/specialist model that represents professional communication in pure form. As a variant, communicants are specialists of different but still related areas of knowledge. This type of communication can be called interprofessional. 2. The second case is the specialist/non-specialist model. In this case communicants are professionally unequal, but still manage to understand each other. We define the non-specialist as a person who has general knowledge in this or that field but who is not professionally involved in it. 3. The case of intraprofessional communication, when professional roles and statuses of communicants are different (for ex., teacher/student, doctor/patient, etc.). In all three cases communicants are professionally oriented.

2. Circumstances of communication.

Every sphere of professional activity (science, technology, education, diplomacy, etc.) is characterized by its own specific circumstances of communication. In other words, there is a limited set of joint practical acts that are typical of this or that SPC. Joint practical acts are performed in certain time (chronological period) and in certain places, the set of which is also limited. There are more of less stable relation between the type of a joint practical act, its place and time, and any deviation makes the situation of communication atypical or even impossible. Circumstances of communication assign functional and communicative roles to participants. They also determine whether speech will be dialogic/monologic, oral/written, direct/indirect forms of communication, official/non-official character of speech, etc.

3. System of communicative intentions.

A considerable variety of practical purposes and, consequently, variety of forms of communication is the result of complexity and versatility of professional activity. Generally speaking, there are three types of professional communication: educational, cognitive and practical. That is to say, people communicate when getting job training, when solving professional problems, and, finally, when working by profession. All diverse communicative intentions that occur in the course of this or that professional activity fall under these basic types. All types are connected with acquisition and application of professional experience. Acquisition and application are always purposeful and intensity of these processes depends on person’s professional interest.

4. Communicative processes.

Speaking about communicative processes (verbalization, understanding, interaction) in the context of PCA, we shall turn to the notion of professional knowledge. Professional knowledge is systematic, comprehensive, and is prepared for immediate recall and use. Consequently, communicative processes that run on the basis of professional knowledge are dynamic and integrative. Verbal-logical thinking prevails in professional activity. Consequently, particular ‘professional’ consciousness, programmability and purposefulness are also typical of such communicative processes. In any way direct study of communicative processes is impossible, as we can judge about them only by their products (utterances, texts).

5. Communicative text.

The first four categories of PCA determine the form and content of a text of this or that sublanguage (a special text). The plane of content of special texts is presented by a topical repertory that covers a limited subject field. As a rule, the notion of the subject field is considered in the context of scientific theory. Scientific theory is a form of organization of scientific knowledge that reflects the structure, regularity and relations of certain limited area of reality. A corpus of special texts of different science disciplines is the basic form of existence of scientific information. That is why the notion of the subject field can be considered not only in relation to the subject matter of this or that scientific theory, but also to some corpus of texts that fix it. A corpus of texts of a limited subject field is a total product of professionally oriented communicants of certain SPC, in which their knowledge and expertise are accumulated and shared.

Now let’s turn to the plane of expression. Two different texts belonging to the same functional style can have almost identical content. To put it in a different way, the same subject matter can have different forms of expression. The structure and linguistic peculiarities of special texts are determined by functional styles and speech genres that are conventional in SPC. As a matter of fact, scientific functional style is always prototypical. It corresponds to ‘professional consciousness’ and conceptual system of a certain scientific field. Linguistic means denoting special concepts (i.e. terms) reach highest concentration in special texts of scientific functional style. On the other hand, other functional styles with their corresponding speech genres can be used more often in some sublanguages (for ex., publicistic style in political sublanguage). Thus, scientific functional style is not always predominant and every SPC has its own unique genre-stylistic characteristic.

Summing it up, anthropocentric approach to sublanguage studies its functioning in communication, from the point of view of “human factor”. We can get an adequate and comprehensive idea of what sublanguage is only if we take it in the context of communicative act, to be more exact, professional communicative act. PCA is characterized by the following parameters: professionally oriented communicants, circumstances of professional communication, system of communicative intentions of professionally oriented communicants, communicative processes of professional communication, special communicative text, which form and content are determined by the sphere of professional communication, in which this communicative act takes place. From the textocentric point of view sublanguage is a system of expressive means that is fixed in the corpus of special texts of a limited subject field. Each sublanguage has its own set of typical functional styles and genres. Genre-stylistic norms observed in the most typical special texts of a certain sublanguage can give us more or less clear-cut idea of its borders.