An object pronoun replaces a noun already identified in the sentence. It avoids repeating the complement after the verb and keeps the meaning clear through the context. In Je vois Marie, Marie can become Je la vois. The pronoun takes the place of the complement and the sentence stays lighter. Without this replacement, the same noun is often repeated unnecessarily. The Pronoms personnels are often used in this role, with other forms depending on the function of the complement.

Choice of the complement according to its function

Idea
We choose a direct object pronoun when the noun answers who or what without a preposition.
We choose an indirect object pronoun when the noun is introduced by à.

The direct object complement answers the question quoi or qui after the verb, with no preposition. The indirect object complement is linked to the verb by a preposition, often à. In Je regarde le film, le film is a COD. In Je parle à Paul, à Paul is a COI. This difference determines the pronoun to choose. The COD often becomes le, la, les; the COI of a person becomes lui or leur. With the Pronoms relatifs, this distinction remains useful, because the function of the noun also changes the form chosen.

Subject	Infinitive	Conjugation
vous	remplacer
tu	remplacer
il	remplacer
ils	remplacer
je	remplacer
nous	remplacer
elle	remplacer

Forms of common object pronouns

Subject	Infinitive	Conjugation
je	remplacer	me
tu	remplacer	te
il	remplacer	le
elle	remplacer	la
nous	remplacer	nous
vous	remplacer	vous
ils	remplacer	les

Scramble

Me, te, nous, vous replace the people who receive the action when they are already known in the sentence. Le, la, les replace a COD of a person or a thing. The choice depends on number and gender for le, la, les: le for a masculine singular noun, la for a feminine singular noun, les for plural. Me and te vary by person, not by gender. We say Il me voit, Je te cherche, Nous les attendons, Elle la prend. The Pronoms personnels provide the base for these subject and object forms, and the Pronoms démontratifs are often used when you want to refer to something without naming it again.

Use of lui and leur with people

Idea
We use lui to replace a single person introduced by à.
We use leur to replace several people introduced by à.

Lui replaces a COI of a person in the singular. Leur replaces a COI of a person in the plural. They often follow a verb built with à: Je parle à Luc becomes Je lui parle; Nous écrivons à nos amis becomes Nous leur écrivons. These pronouns do not change according to the gender of the person. They do not replace a COD. For an action directed at a person after à, these are the forms to remember. The Pronoms possessifs express ownership, while lui and leur indicate the grammatical relationship with the verb.

Position of the pronoun near the conjugated verb

Usage	Explanation
Affirmative sentence	In an affirmative sentence, the pronoun is placed before the conjugated verb.
Negative sentence	In a negative sentence, the pronoun stays before the conjugated verb and the negation frames it.

In an affirmative sentence with a conjugated verb, the object pronoun sits before the verb. We say Je le vois, Tu lui réponds, Ils les connaissent. In the negative form, the pronoun stays before the verb, between ne and the conjugated verb: Je ne le vois pas, Nous ne leur parlons pas. With a compound tense, the pronoun precedes the auxiliary: Elle l’a pris, Ils nous ont appelés. The placement does not change depending on the meaning of the pronoun; it follows the sentence’s verbal structure.

Placement before or after the infinitive

Usage	Explanation
Conjugated verb then infinitive	When a verb is followed by an infinitive, the pronoun is placed before the infinitive if the meaning depends on the second verb.
Infinitive with two verbs	With two verbs, the pronoun keeps the link with the infinitive to avoid any ambiguity.

When a verb is followed by an infinitive, the pronoun sits before the infinitive. We say Je vais le faire, Nous voulons lui parler, Elle préfère les acheter. The structure is therefore subject + conjugated verb + pronoun + infinitive. If two verbs follow each other, the pronoun does not go in front of the first conjugated verb when the main action is carried by the infinitive. With the verbs of Pronoms réfléchis, the same position before the infinitive appears in phrases like Je vais me lever.

Pronoun after the affirmative imperative

Usage	Explanation
Simple affirmative order	In the affirmative imperative, the pronoun sits after the verb with a hyphen.
Affirmative order with multiple pronouns	In the affirmative imperative, you can add another pronoun after the verb to specify the person concerned.

In the affirmative imperative, the pronoun sits after the verb and is connected by a hyphen: Donne-le, Explique-lui, Parlez-nous. With me and te, the form becomes moi and toi: Aide-moi, Regarde-toi. In the negative imperative, the pronoun comes before the verb as in a normal sentence: Ne le donne pas, Ne leur parle pas. This difference depends only on affirmation or negation.

Replacement of already-known nouns

Idea
We replace a noun already mentioned with a complementary pronoun to avoid heavy repetition.
We keep the sentence lighter when the same noun occurs several times.

When the same noun appears in two neighboring sentences, the object pronoun allows you to refer to it again without heaviness. La serveuse apporte le plat. Les clients le regardent. Elle le sert. The meaning remains clear because the context already provides the information. In a conversation, this repetition makes the speech more natural: Tu connais cette chanson ? Oui, je la connais. The Pronoms indéfinis are used when you do not specify exactly the person or thing, but here the complement is already identified.

Uses of y with à

Usage	Explanation
Place	We use y to replace a place already mentioned.
Idea introduced by à	We use y to refer to an idea built with à.

Y mainly replaces a place introduced by à or a place name already known: Je vais à Paris becomes J’y vais. It also replaces an idea or a thing introduced by à: Je pense à mon travail becomes J’y pense. The sentence preserves the same structure, but the complement disappears in favor of the pronoun. Y does not replace a person. It serves for a place, an location, a situation, or an idea related to à.

Uses of en with quantity and origin

Usage	Explanation
Quantity	We use en to refer to a quantity already known.
Origin	We use en to talk about an origin or provenance.
Part of a whole	We use en when we talk about only part of something.

En often replaces a complement introduced by de. It can indicate a part, a quantity, or an origin. We say J’ai du pain. J’en ai, Nous avons trois chats. Nous en avons trois, Il revient de Lyon. Il en revient. With a quantity, en often keeps the number or the quantity expression: J’en veux deux, Elle en boit beaucoup. It also replaces something already mentioned when the verb calls for de. The Pronoms relatifs will organize the information in another structure later, but here en directly takes back the complement.