The Personal Pronouns Indirect Object replace words that have the function of an indirect object in the sentence. They precede intransitive verbs that are used with the preposition: à, au, aux. They answer the question: “A qui?” or “A quoi”.
Study the following example:
J’ai demandé à mon professeur la permission de sortir.
I asked my teacher the permission to leave.
Je lui ai demandé la permission de sortir.
I asked him the permission to leave.
“lui” is a personal pronoun that replaces “mon professeur” which has a function of an indirect object in this sentence. It answers the following question: “J’ai demandé à qui?” “ à mon professeur”.
Study the following example:
J’ai demandé à mon professeur la permission de sortir.
I asked my teacher the permission to leave.
Je lui ai demandé la permission de sortir.
I asked him the permission to leave.
“lui” is a personal pronoun that replaces “mon professeur” which has a function of an indirect object in this sentence. It answers the following question: “J’ai demandé à qui?” “ à mon professeur”.