Investigating Diachronic changes and Synchronic differences of the verb Xāstan on the basis of Cognitive approach of basic event Schemas

This paper is concerned with the investigation of diachronic changes and synchronic differences of the verb 'Xāstan' on the basis of grammaticalization process of basic event schemas in the framework of Cognitive Linguistics. Basic event schemas, are simple semantic units that consist of a predicate and associated variables. These schemas express general and basic notions that establish grammatical structures in any language.
In this paper, one of these basic schemas, i.e., the 'Volition' schema ([X wants Y]) was brought under consideration and it was revealed that by applying this schema on the Persian lexical verb 'Xāstan', the basic notion 'what one want's is expressed in Farsi.
Findings: It was revealed that by applying the process of grammaticalization on the volition schema, it transforms into a complex one known as a 'serial schema' ([X wants # [X] VERB Y]) with the meaning 'what one wants to do'. The process of grammaticalization continues with the effect of transforming the serial schema to 'Future schema' ([X Y # want (to) VERB]). The final result of this process is changing the lexical verb 'xāstan' to auxiliary verb 'Xāstan' with the effect of expressing the actions that occur in future tense.
Simultaneous investigation of diachronic and synchronic changes of the verb 'Xāstan' and clarifying the point that grammaticalization applies not only on the lexical verb but also on the whole structure of the basic event schema are among the achievements of this paper.