¿No me harías un favorcito? “Wouldn’t you do me a little favor?” The request is softened three times, with a negative, the conditional and a diminutive. It is the title of a 1998 study of verbal politeness in Mexican Spanish by the linguist Carmen Curcó.
In 2002, Curcó and Anna De Fina published a study of imperatives, negation and diminutives in polite speech. A doctoral thesis at El Colegio de México sums up its finding: “los mexicanos valoran como más corteses los enunciados en que se atenúa la fuerza ilocutiva” (Mexicans rate as more polite the utterances in which the force of the request is softened).