In Spanish, there are some expressions that are hidden behind another word in a certain way. This is the case of the pronoun Se. When there is an indirect object pronoun Le that refers to the personal pronouns he, she, you or Les that refers to the personal pronouns they, you and is followed by a direct object pronoun Lo, La, Los, Las what you should do is to change the pronouns le or les with a “disguise” called se.
This happens because there is a grammatical rule that says the following: If we want to join the direct object and the indirect object within a verb, the first thing that goes is the indirect object followed by the direct object. However, in the event that the indirect object is le or les, it is necessary to replace it with the pronoun se.
- El niño le dio la pelota a su padre.
Writing el niño le la dio is incorrect, —-> The correct answer is: el niño se la dio
2. Los profesores corrigieron los exámenes a los alumnos.
Writing Los profesores les los corrigieron is incorrect —-> The correct answer is: los profesores se los corrigieron
3. María compra una tarta a su mejor amiga.
Writing María le la compra is incorrect —-> The correct answer is María se la compra
It is for this reason that we say that in these cases the pronoun se «disguising» itself in order to make the sentence better heard.