Les pronoms compléments d'objet indirect (COI)

An indirect object is the person (almost always a person, in practice) that a verb's action is directed toward, marked in French by the preposition à — 'to give to someone,' 'to speak to someone,' 'to write to someone.' When that indirect object is a person already known from context, French replaces à + person with an indirect object pronoun (COI, complément d'objet indirect) rather than repeating the full phrase. The indirect object pronouns are: me (to me), te (to you, informal), lui (to him or to her — lui does not distinguish gender), nous (to us), vous (to you, formal/plural), and leur (to them, both genders). Notice that me, te, nous, and vous are identical in form to the direct object pronouns you learned in the previous unit — only the third-person forms differ: lui/leur (indirect) versus le/la/les (direct).

Just like direct object pronouns, indirect object pronouns are placed before the conjugated verb, not after it as in English: je lui parle (I speak to him/her — literally 'I to-him/her speak'), not je parle lui. In two-verb constructions, the pronoun attaches to the infinitive: je vais lui téléphoner (I'm going to call him/her). In the negative, ne comes before the pronoun and pas comes after the conjugated verb: je ne leur écris pas (I don't write to them). In the passé composé, the pronoun goes before the auxiliary: je lui ai parlé (I spoke to him/her) — and importantly, past participles never agree with a preceding indirect object, unlike with direct objects, so ai parlé stays unchanged regardless of gender or number.

The hardest part of this unit is usually not the pronouns themselves but figuring out which verbs take à + person (and therefore lui/leur) versus which take a direct object (and therefore le/la/les), because English often doesn't preserve the same distinction. Common French verbs that take an indirect object (à quelqu'un) include: parler à (to speak to), téléphoner à (to phone), écrire à (to write to), donner à (to give to), demander à (to ask), répondre à (to answer/respond to), and, importantly for this clothing/shopping unit, plaire à (to please/be pleasing to — used for 'to like' in a flipped construction: ce pull te plaît, literally 'this sweater is pleasing to you,' meaning 'you like this sweater'), and aller à (to suit, as in 'to look good on' someone: cette robe lui va bien — that dress suits her). Compare these with verbs like regarder (to watch), écouter (to listen to), attendre (to wait for), and chercher (to look for), which take a direct object in French even though their English translations include a preposition — these take le/la/les, not lui/leur.

A reliable test: try rephrasing the English sentence using 'to' explicitly before the person — 'I speak to him' works, confirming an indirect object; but 'I watch to him' sounds wrong, because 'watch' takes a direct object even though French learners sometimes assume otherwise. When in doubt, look up the verb's preposition pattern (verbe + à quelqu'un vs. verbe + quelqu'un) rather than translating instinctively from English.