Indefinite relative pronouns (ce qui, ce que, ce dont)

Je ne sais pas ce qui se passe.Voici ce que je pense.C'est exactement ce dont j'ai besoin.I don't know what's happening.Here's what I think.That's exactly what I need.

Qui, que, où and dont all replace a specific noun already mentioned. But sometimes there's no noun to point back to at all — only a vague "what" or "the thing that", or a whole idea from earlier in the sentence. That's the job of ce qui, ce que and ce dont: each pairs the neutral placeholder ce with the ordinary relative pronoun that fits the missing role.

Quick shortcut: pick the ending exactly as for a normal relative clause — subject → ce qui, direct object → ce que, de-role → ce dont — just with no specific noun in front.

Ce qui: subject of the clause

Ce qui is the subject of its own clause, standing in for an unspecified thing or situation:

• Je ne sais pas ce qui se passe. (I don't know what's happening.) — ce qui is the subject of se passe.
• Ce qui compte, c'est ta santé. (What matters is your health.) — ce qui is the subject of compte.
• Dis-moi ce qui t'inquiète. (Tell me what's worrying you.)

Because ce qui is a subject, the verb right after it agrees with it (third person singular) — it behaves exactly like qui in an ordinary relative clause, just without a specific antecedent noun.

Ce que: direct object of the clause

Ce que stands in for an unspecified thing as the direct object of its clause:

• Voici ce que je pense. (Here's what I think.) — ce que is the direct object of pense.
• Montre-moi ce que tu as acheté. (Show me what you bought.)
• Je ne comprends pas ce que tu veux dire. (I don't understand what you mean.)

Like ordinary que, ce que elides to ce qu' before a word starting with a vowel or a mute h — never before a consonant, and ce qui never elides, whatever follows it:

• *Dis-moi **ce qu'*elle veut. (Tell me what she wants.)
• *J'ignore **ce qu'*il a dit. (I have no idea what he said.)
• ✅ Je ne sais pas ce qui arrive, never ❌ ce qu'arrive — qui is never elided.

Ce dont: a complement directly introduced by de

Ce dont stands in for an unspecified thing that's the direct de-complement of a verb or adjective that's normally followed by de (avoir besoin de, parler de, avoir envie de, être content de...):

• C'est exactement ce dont j'ai besoin. (That's exactly what I need.) — from j'ai besoin de quelque chose.
• Voilà ce dont je parlais. (There's what I was talking about.) — from je parlais de quelque chose.
• Je ne sais pas ce dont elle a envie. (I don't know what she wants.)

Exactly as with dont and a specific noun, once ce dont is used, the de it replaces never reappears later in the clause. And exactly as with dont, ce dont only replaces a bare, single-word de — not de buried inside a longer preposition like à propos de or au sujet de; those need a different pronoun, a more advanced topic of its own.

Referring back to a whole idea

Ce qui, ce que and ce dont also introduce a comment on an entire preceding clause, not just a single word — a very common pattern in everyday speech:

• Il pleut, ce qui m'ennuie. (It's raining, which annoys me.) — ce qui refers to the whole fact that it's raining, and is the subject of m'ennuie.
• Elle a réussi son examen, ce que j'espérais. (She passed her exam, which I was hoping for.) — ce que is the direct object of espérais, standing for the whole preceding fact.
• Il est toujours en retard, ce dont tout le monde se plaint. (He's always late, which everyone complains about.) — from se plaindre de quelque chose.

The choice between ce qui/ce que/ce dont here still follows the same rule as everywhere else: it depends on the role the idea plays in the second clause, never on what came before the comma.

Common mistakes

• ❌ Je ne sais pas qui se passe. → ✅ Je ne sais pas ce qui se passe. (dropping ce — there's no antecedent noun, so the bare relative pronoun can't stand alone)
• ❌ Voici que je pense. → ✅ Voici ce que je pense. (same mistake with que)
• ❌ C'est ce que j'ai besoin. → ✅ C'est ce dont j'ai besoin. (avoir besoin de needs the de-pronoun ce dont, not ce que)
• ❌ *Dis-moi **ce qu'*arrive. → ✅ Dis-moi ce qui arrive. (ce qui never elides)

Quick check

Key takeaways

• Ce qui, ce que and ce dont are used instead of qui, que and dont when there's no specific noun to point back to — only an unspecified thing ("what") or a whole preceding idea.
• The choice still follows the role in the clause: subject → ce qui, direct object → ce que, de-role → ce dont.
• Ce que elides to ce qu' before a vowel or mute h; ce qui never elides.
• All three can also comment on an entire preceding clause (Il pleut, ce qui m'ennuie), not just a single unspecified thing.