Indefinite relatives (ce qui, ce que, ce dont)
Summary
ce qui, ce que and ce dont introduce a relative clause whose antecedent is not a specific noun but a whole idea, clause, or unnamed thing ("what / that which"). The choice depends on the grammatical role inside the clause: subject, object, or complement with de.
Explanation
Ordinary relative pronouns (qui, que, dont, où) refer back to a specific noun: « le livre qui… », « la femme que… ». The indefinite relatives ce qui, ce que and ce dont are different: their antecedent is not a noun but a whole idea, a preceding clause, or something unnamed. They correspond to English "what" or "that which": « Je ne comprends pas ce qui se passe. » (I don't understand what is happening).
The choice among the three depends solely on the grammatical function of ce inside the relative clause — exactly the same logic as qui / que / dont with a noun antecedent. Ce qui is the subject of the relative verb, so a verb follows directly: « ce qui m'intéresse » (what interests me), « Dis-moi ce qui ne va pas. » Ce que (elided to ce qu' before a vowel) is the direct object, so a subject + verb follow: « ce que je veux » (what I want), « ce qu'il a dit » (what he said).
Ce dont is used when the verb or expression inside the clause is constructed with the preposition de. Since dont already contains de, you never repeat the preposition: « ce dont j'ai besoin » (what I need, from avoir besoin de), « ce dont tu parles » (what you are talking about, from parler de), « ce dont il a peur » (what he is afraid of, from avoir peur de). A frequent error is to say *ce que j'ai besoin*; the verb governs de, so ce dont is required.
These indefinite relatives are also used to sum up a whole preceding clause, often after a comma, where ce qui / ce que refer back to everything just said: « Il est arrivé en retard, ce qui m'a énervé. » (He arrived late, which annoyed me), « Elle a tout réussi, ce que personne n'attendait. » Here "which" does not point to one noun but to the entire previous statement.
Finally, the neutral antecedent ce is often reinforced by tout to mean "everything that": tout ce qui (everything that — subject), tout ce que (everything that — object), tout ce dont (everything that — with de). « Tu peux prendre tout ce que tu veux. » (You can take everything you want), « C'est tout ce qui compte. » (That's all that matters). The same subject/object/de distinction applies, simply preceded by tout.
Examples
Dis-moi ce qui te ferait plaisir. — Tell me what would make you happy. (ce qui = subject (a verb follows directly).)
Je n'ai pas compris ce que tu as dit. — I didn't understand what you said. (ce que = object (subject tu + verb follow).)
Voilà exactement ce dont j'avais besoin. — That's exactly what I needed. (avoir besoin de → ce dont (de is built into dont).)
Il a refusé de m'aider, ce qui m'a beaucoup déçu. — He refused to help me, which disappointed me a lot. (ce qui sums up the whole preceding clause.)
Tu peux commander tout ce que tu veux. — You can order everything you want. (tout ce que = everything that (object).)
Ce dont nous parlons est confidentiel. — What we are talking about is confidential. (parler de → ce dont as the sentence subject.)
Common mistakes
Je ne sais pas qu'est-ce qu'il veut.
Je ne sais pas ce qu'il veut.
qu'est-ce que is the form used only in direct questions. In an indirect question embedded after a verb like savoir, French uses ce que (or ce qui for the subject), never qu'est-ce que: je ne sais pas ce qu'il veut.
Prerequisites
Related rules
pronounsrelative-clausessyntax