lysis of the grammar is taken from a trinocular perspective, meaning from three different levels. So to look at lexicogrammar, we can analyze it from two more levels, ‘above'(semantic) and ‘below’ (phonology). This grammar gives emphasis to the view from above.
For Halliday, grammar is described as systems not as rules, on the basis that every grammatical structure involves a choice from a describable set of options. Language is thus a meaning potential. Grammarians in SF tradition use system networks to map the available options in a language. In relation to English, for instance, Halliday has described systems such as mood, agency, theme, etc. Halliday describes grammatical systems as closed, i.e. as having a finite set of options. By contrast, lexical sets are open systems, since new words come into a language all the time.
These grammatical systems play a role in the construal of meanings of different kinds. This is the basis of Halliday’s claim that language is met functionally organized. He argues that the raison d’être of language is meaning in social life, and for this reason all languages have three kinds of semantic components. All languages have resources for construing experience (the ideational component), resources for enacting humans’ diverse and complex social relations (the interpersonal component), and resources for enabling these two kinds of meanings to come together in coherent text (the textual function). Each of the grammatical systems proposed by Halliday is related to these metafunctions. For instance, the grammatical system of ‘mood’ is considered to be centrally related to the expression of interpersonal meanings, ‘process type’ to the expression of experiential meanings, and ‘theme’ to the expression of textual meanings.
Traditionally the “choices” are viewed in terms of either the content or the structure of the language used. In SFG, language is analyzed in three ways (strata): semantics, phonology, and lexicogrammar. SFG presents a view of language in terms of both structure (grammar) and words (lexis). The term “lexicogrammar” describes this combined approach.
According to Hallidayan theory structure, structure of a language embraces the realization of the system of that language. Therefore, structure is the surface-level manifestation of grammar. There is also a very close relation between functions of language and language itself .The contribution of systemic grammar has been materialized in different perspectives (Borschev and Partee, 2002: Fries, 1994, 1995, Martin, 1992).The proponents of SFG approach maintain that discourse does not allow linguistic forms to be purposelessly organized. In fact, linguistic elements bear a specific function in their own right. In other words discourse analysis tries to penetrate deeply into the interwoven relationship between syntax and semantics. The generic moves also facilitate the development of well-organized RAs. Moves in genre analysis play the role of traffic sign indicating main headings and points of the whole text of articles. (Khani&Mansoori Nejad, 2010).
1.6.2 Rhetoric
Is the art which seeks to capture in opportune moments that which is appropriate and attempts to suggest that which is possible. Rhetoric is an artistic undertaking which concerns itself with the how, then when and what of expression and understands the why of purpose. (John Poulakos, contemporary rhetorical theory edited by John Louis Lucaites, Celeste Michelle Condit, Sally Caudill).
Theory of rhetoric: is obviously fundamental to contrastive rhetoric. It is interested in assessing the direct or indirect effect of communication on the hearer or reader. Kaplan’s first model of contrastive rhetoric was based on Aristotelians rhetoric and Logic. Naturally, rhetoric, and especially modern rhetoric, is interested in the situational relativity of communicative effectiveness. Research on writing as a social construction of meaning has shown the value of examining perceptions and beliefs about literacy and learning in writing classrooms (Hulletal, 1991).Based on theory of rhetoric, writing as communication and persuasion is affected by audience.
Rhetorical theory is the body of thought about human symbol use. The term rhetoric, in its popular usage, typically has negative connotations. Rhetoric is contrasted with action; it is empty words, talk without substance, mere ornament.
This contemporary understanding of rhetoric is at odds with a long history of rhetorical theory, dating back in the West to ancient Greece and Rome, that provides a long-standing foundation on which the contemporary discipline of communication is built at the heart of theorizing about rhetoric, whether for the Greeks or contemporary scholars, is what came to be called by Lloyd Bitzer in 1968 the rhetorical situation. Rhetoric occurs in response to an exigency or some kind of urgency, problem, or something not as it should be. Another characteristic of the situation is the audience- those individuals capable of affecting the exigency in some way. In addition, there are constraints in the situation-positive and negative factors that hinder or enhance the possibility that the audience will be able to affect the exigency. Rhetoric comes into being, then, when rhetoric observes or creates an exigency and offers discourse designed to bring the interests of the audience to bear on it. In essence, then, rhetorical theorists address some or all parts of the rhetorical situation-the rhetoric and the degree of agency available to him or her; the audience and the constraints available to them; the discourse, message, or symbols used to address the exigency; how the exigency itself is constructed, created, and addressed; and the larger contexts- historical, economic, cultural, and symbolic-in which the situation is playing out. This entry will discuss definitions of rhetoric, origins of rhetorical theory, and some of the major developments and elaborations on rhetorical theory since its classical beginnings.
1.6.3 Teaching English for Specific Purposes (ESP)
ESP was and is a controversial issue among EFL teachers and others.ESP teaching develops procedures appropriate for learners whose main purpose is learning English for a purpose other than just learning the language system (Davoodifard and Eslami Rasekh , 2005).

The meaning of the word “specific” that goes with the term English for Specific Purposes does not mean “specialized”, and the aim of teaching ESP is not to teach special terminology or jargon in a specific field of study (Maleki,
2005), ESP teachers play important role in their field. Rarely, have the studies delved into teachers’ knowledge about grammar (reviewed by Borg.2001) or investigated the relationships between teachers’ knowledge about grammar and teachers’ actions (Borg, 2003; Sanchez, 2010).
From the book of Dudley Evans (1998) entitled ‘Developments in English for Special Purposes’ it is said that The