@dconley I'm not being very clear, but here's a better designed explanation of direct objects:
https://witches.town/@candle/887378
And so, INDIRECT objects (COI in French, for "complément d'objet indirect") will usually be indicated by a preposition (unless they're hidden in a pronoun because we're very twisted with our pronouns), to inform you they're not the CoD (the direct object). It's a bit technical, like all French grammar, but quite useful. :<