DIRECT pronoun or INDIRECT pronoun? 1

Direct object pronouns — replacing what — DOPs replace the direct object (the thing or person directly receiving the action): me, te, lo/la, nos, os, los/las. Ask "what?" or "whom?": ¿Ves el libro? → ¿Lo ves? ¿Llamaste a María? → ¿La llamaste? The pronoun must match the gender and number of the replaced noun.

Indirect object pronouns — replacing to/for whom — IOPs replace the indirect object: me, te, le, nos, os, les. Ask "to whom?" or "for whom?": Doy el libro a Juan → Le doy el libro. Note that IOPs only have two 3rd-person forms (le/les) — there is no gender distinction, unlike DOPs.

Clarifying le/les with a noun phrase — Because le/les can mean to him, to her, to you (formal), or to them, Spanish often adds a clarifying phrase: Le escribí a ella. Les expliqué a los estudiantes. The IOP stays in the sentence — the a + noun/pronoun phrase simply clarifies who le/les refers to.