Relative pronouns let you combine two sentences by turning one of them into a descriptive clause attached to a noun, avoiding repetition — much like English "who," "which," and "that." French has two basic relative pronouns to master first: qui and que. The choice between them depends entirely on the grammatical role the pronoun plays inside the clause it introduces — not on whether the noun is a person or a thing, which is the trap English speakers fall into (since English "who" vs. "that/which" splits along person/thing lines instead).
Qui is used when the relative pronoun is the subject of the verb that follows it — that is, when it's the one doing the action in the relative clause. La femme qui parle est ma tante (The woman who is speaking is my aunt): qui is the subject of parle. Because qui is a subject, it is immediately followed by a conjugated verb, with nothing in between, and it is never elided (never qu' before a vowel) — you always write qui even before a word starting with a vowel: la personne qui arrive.
Que (which becomes qu' before a vowel sound) is used when the relative pronoun is the direct object of the verb that follows it — that is, when the noun being described is having the action done to it, not doing it. Le livre que je lis est passionnant (The book that I'm reading is fascinating): que is the object of lis (I am reading it — the book). Because que is an object, it's always followed by a subject + verb (a noun or pronoun doing the action), never directly by a conjugated verb on its own. A fast diagnostic: if you can immediately insert a new subject after the relative pronoun and before the verb, you need que; if the verb comes right after the relative pronoun with nothing in between, you need qui.
Critically, in the passé composé, when que refers to a preceding direct object, the past participle must agree in gender and number with that object — this is one of the more advanced agreement rules in French. La pomme que j'ai mangée (the apple that I ate) adds an -e to mangé because pomme is feminine and que stands in for it, appearing before the verb. This agreement never happens with qui, because qui is a subject, not a preceding direct object, so the participle stays in its default form: L'homme qui a mangé la pomme (no agreement, since qui is the subject, not a preceding object).
Exemples
La femme qui parle est ma tante.
The woman who is speaking is my aunt.
qui = subject of 'parle'
Le livre que je lis est passionnant.
The book that I'm reading is fascinating.
que = object of 'lis'
J'ai un ami qui habite à Lyon.
I have a friend who lives in Lyon.
qui refers to a person, but that's not why qui is chosen — it's because it's the subject.
Le film que nous avons vu était excellent.
The movie that we saw was excellent.
que = object of 'avons vu'
C'est le stylo qui ne fonctionne plus.
That's the pen that doesn't work anymore.
qui refers to a thing — proof that qui isn't only for people.
Voici la maison que mes parents ont achetée.
Here's the house that my parents bought.
Past participle agrees with 'maison' (feminine) because que stands in for it as a preceding direct object.
Les élèves qui étudient réussissent souvent.
Students who study often succeed.
qui = subject of 'étudient'
C'est un problème que je ne comprends pas.
It's a problem that I don't understand.
que = object of 'comprends'
Le chat qui dort sur le canapé s'appelle Milo.
The cat that is sleeping on the couch is named Milo.
qui = subject of 'dort'
Les amis que j'ai invités arrivent bientôt.
The friends that I invited are arriving soon.
Past participle agrees with 'amis' (masc. plural) → invités
Erreurs fréquentes
- Choosing qui or que based on whether the noun is a person or a thing, mirroring the English who/which split, instead of checking whether the pronoun is the subject or object of its clause.
- Eliding qui before a vowel (writing 'qu'arrive' instead of 'qui arrive') by wrongly assuming both relative pronouns elide the same way.
- Forgetting past participle agreement when que refers to a preceding feminine or plural direct object (writing 'la maison que mes parents ont acheté' instead of 'achetée').
- Inserting an extra subject pronoun after qui (writing 'la femme qui elle parle' instead of 'la femme qui parle'), treating qui as if it still needed its own subject.
- Using que where qui is required because the clause 'sounds like' it needs an object pronoun, without actually checking whether a verb or a new subject follows.
Pourquoi ça trompe les anglophones
- English splits relative pronouns by animacy (who = person, which/that = thing), so English speakers default to that logic instead of the French rule, which splits by grammatical function (subject vs. object) regardless of whether the antecedent is a person or thing.
- The past-participle agreement triggered by a preceding 'que' has no equivalent whatsoever in English, where past participles never change form to match anything, making it a rule that has to be consciously layered on top of already-learned passé composé patterns.
- Both qui and que translate to overlapping English words ('who', 'that', 'which'), so learners can't rely on translation to pick the right one and must instead analyze French sentence structure directly.