Although the suffix -le hypothesis as influence of Nahuatl has been widely questioned; Navarro Ibarra (2009) finds another explanation about -le intensifying character. The author warns that it is a defective dative clitic; instead of working as an indirect object pronoun, it modifies the verb. An effect of the modification is the intransitive of the transitive verbs that appear with this -le defective (ex. "moverle" "to move" it is not "mover algo para alguien" "to move something for someone" but "hacer la acción de mover" "to make the action of moving"). This intensifier use is a particular grammatical feature of the Mexican Spanish variant. In any case, it should not be confused the use of -le as verbal modifier, with the different uses of the pronouns of indirect object (dative) in the classical Spanish, as these are thoroughly used to indicate in particular the case genitive and the ethical dative. In what is considered one of the founding documents of the Spanish language, the poem of Mio Cid written around the year 1200, you can already find various examples of dative possessive or ethical.