This research describes the generalization processes that seventh grade students (11-13 years old) carried out when developing tasks associated with algebraic contexts, mediated by pattern recognition and its representations, where semiotic representations and transformations made by students were identified. Likewise, relationships were established between such representations and the arithmetic and algebraic generalization processes, that is, semiotic representations were a link for the development of expressions that show the way students develop algebraic thinking. For the identification of the generalization processes, Radford (2013) and Mason (1996) were taken as references, establishing relations between the structure and the algebraic generalization processes. Finally, it was shown that the use of diverse representations in intermediate languages, their transformations (treatment and conversion) and the recognition of patterns, make possible for students to make a transition between arithmetic and algebraic generalization.