According to the extended projection principle (EPP), it is claimed that all sentences require subjects. In line with such assumption, it is believed that some languages, including Persian, are categorized as pro-drop languages and their subject is encoded by the verbal inflection. In fact, the subject position is an empty category designated by pro (small pro). Therefore, AGR (verbal inflection) has a purely syntactic function. However, in cognitive grammar, AGR is treated as a symbolic assembly profiling a process whose only independent contribution to the meaning of the verb with which it combines, is the person and number specification of the processual AGR. Considering AGR as a meaningful category, its trajector can correspond with the trajector of the processual component (verb) which is left unexpressed. In contrast to the assumption that AGR is redundant, it shown that the subject (the trajector of the processual component) is not dropped; it does exist but is highly schematic. It is elaborated (becomes specific) by trajector of AGR through correspondence. In other words, Persian speakers conceptualize the subject by only one source of information; that is the trajector of AGR.
