An indirect object is the person or thing in a sentence that receives the action but is not the primary object. Indirect pronouns replace the indirect object which is always a living thing.

Indirect objects are placed in front of the verb.

Formula:
Subject-Pronoun-Verb

Example:
Je lui ai donné le livre

Indirect Object Pronouns

Me/M'
Te/T'
Lui
Nous
Vous
Leur