In French, the words qui and ce qui both translate to “who” or “which” in English, but they serve different grammatical purposes. Qui tends to mean “who” or “which,” while ce qui tends to mean “what” or “that which.”

1. “Qui” as a Relative Pronoun

Qui functions as a relative pronoun referring to a previously mentioned noun (the antecedent). It is used as the subject of the relative clause and can refer to people or things.

Examples:

• La femme qui parle est ma sœur. (The woman who is speaking is my sister.)
• Le livre qui est sur la table est intéressant. (The book which is on the table is interesting.)
• Les étudiants qui étudient réussiront. (The students who study will succeed.)

In these examples, qui directly connects to a noun (la femme, le livre, les étudiants) and introduces a clause where it acts as the subject.

2. “Ce Qui” as an Indefinite Relative Pronoun

Ce qui does not refer to a specific noun but instead introduces a general idea or an entire clause. It means “what” or “that which” and serves as the subject of the relative clause.

Examples:

• Ce qui m’intéresse, c’est la science. (What interests me is science.)
• Je ne comprends pas ce qui s’est passé. (I don’t understand what happened.)
• Dis-moi ce qui te plaît. (Tell me what you like.)

Here, ce qui does not replace a specific noun but rather refers to an undefined subject or concept.

Key Differences

Feature	Qui	Ce Qui
Reference	Refers to a specific noun	Refers to a general idea
Function	Subject of the relative clause	Subject of an indefinite clause
Example	L’homme qui parle (The man who speaks)	Ce qui compte, c’est l’effort (What matters is the effort)