I was somewhat confused with how "pour" did not turn into an indirect object pronoun when followed by a moi (Il l'achète pour moi)
I asked why on Duolingo, and an individual said it was the object of a preposition, and that a prepositional phrase can be used instead of an indirect object.
His example was: "Il me lit une histoire" and "Il lit une histoire à moi."
I thought this was quite confusing, as he did not describe any rules; he said they're interchangeable with different meaning being construed whether one uses a prepositional phrase or indirect object pronoun.
Are there any rules regarding when to use a prepositional phrase instead of an indirect object? Are there prepositions where a prepositional phrase is required over an indirect object (My thought was "pour" and "avec" must be used instead of an indirect object pronoun)?
Thanks in advance,