A direct object receives the action of the verb with no preposition in between ("I see Marc," not "I see to Marc"). French replaces that direct object with a short pronoun, placed in a very different spot than English puts it.
1. The pronouns
| me (m') | me |
| te (t') | you (informal) |
| le / la (l') | him, her, it |
| nous | us |
| vous | you (formal/plural) |
| les | them |
2. Position: before the conjugated verb
Unlike English, the pronoun goes before the verb, not after.
| Je vois Marc. → Je le vois. | I see him. (not "je vois le") |
| Tu aimes cette chanson ? → Tu l'aimes ? | Do you like it? |
| Il regarde les enfants. → Il les regarde. | He's watching them. |
3. With an infinitive: before the infinitive
When the verb that "owns" the object is an infinitive (after aller, vouloir, pouvoir...), the pronoun attaches to that infinitive, not to the conjugated verb.
| Je vais le voir demain. | I'm going to see him tomorrow. |
| Elle veut les acheter. | She wants to buy them. |
4. Watch out: past participle agreement
Only in the passé composé: when a direct object pronoun comes before avoir, the past participle agrees with it in gender and number, something that never happens when the object stays after the verb. J'ai vu Marie. (no agreement, object after) vs. Je l'ai vue. (agreement, l' = la = feminine, so vue gets an -e).
5. Quick reference
| me, te, le/la, nous, vous, les | go right before the conjugated verb (or the infinitive) |
| le/la → l' | before a vowel sound |
| passé composé | past participle agrees with a preceding direct object pronoun |