The indirect object is the person or thing that receives the benefit or harm of the verb's action. It usually answers the question "to whom?" or "for whom?". In Spanish, it can be expressed with a phrase with "a" or with an indirect object pronoun.

The indirect object pronouns in Spanish are me, te, le, nos, os, and les. They replace the indirect object to avoid repetition. The pronoun retains the function of indicating who receives the effect of the action.

In a simple sentence, the indirect object pronoun goes before the conjugated verb. The pronoun is placed immediately before the verb and preserves the sense of to whom the action is directed.

When there is a conjugated verb and an infinitive, the pronoun can go before the conjugated verb or attached to the infinitive. Both options are correct and keep the same meaning.

With a gerund, the pronoun can go before the auxiliary verb or attached to the gerund. The choice is a matter of placement, not meaning.

In the affirmative imperative, the pronoun attaches to the verb. In the negative imperative, the pronoun goes before the verb.

In Spanish, it's common to use the indirect object pronoun together with the 'a' phrase for clarity or emphasis. This redundancy is acceptable when the recipient is mentioned explicitly.

Le is used with a singular recipient and les with a plural recipient. Agreement depends on how many people receive the action, not on how many objects are delivered.

In some regions, 'le' is used instead of 'lo' for the masculine animate direct object, especially with people. This is called leísmo and is common in the Spanish of Spain, but it does not change the indirect object.

The direct object receives the action of the verb more immediately, and the indirect object is the recipient or beneficiary. In pronouns, "lo/la/los/las" are direct and "me/te/le/nos/os/les" are indirect.