Answer: Yo compré un reloj a Pedro. Yo se lo compré.
Translation: I bought a watch for Pedro. I bought it for him.
Step-by-step explanation:
In this sentence there is a direct object pronoun (lo) and an indirect object pronoun (se). The direct object pronoun replaces the direct object (reloj) and agrees in gender and number with the direct object (lo). The indirect object pronoun replaces the indirect object (Pedro) and agrees in number (singular) with the indirect object (le). When the direct object pronoun and the indirect object pronoun appear together in the same sentence, the direct object pronoun is always written first and when the two pronouns begin with the letter "l", the indirect object pronoun is replaced by "se". "Le lo" are changed to "Se lo".
Spymore