French Relative Clauses

A relative clause, also known as une proposition subordonnée relative, is a particular kind of subordinate clause that is introduced by a relative pronoun rather than a subordinating conjunction. These sentences contain relative clauses, indicated by the brackets:

L'actrice [qui a gagné] est très célèbre.
The actress who won is very famous.

L'homme [dont je parle] habite ici.
The man that I'm talking about lives here.

Clauses, Subordinate Clauses and Relative Clauses

In French, there are three types of clauses, each of which contains a subject and a verb: the independent clause, the main clause, and the subordinate clause. The subordinate clause, which does not express a complete idea and cannot stand alone, must occur in a sentence with a main clause, and it may be introduced by either a subordinating conjunction or a relative pronoun. 

The relative clause is a type of subordinate clause that can only be introduced by a relative pronoun, never by a subordinating conjunction. A French relative pronoun links a dependent or relative clause to a main clause.  

Relative Pronouns

French relative pronouns may replace a subject, direct object, indirect object, or preposition. They include, depending on context, que, qui, lequel, dont and où and generally translate into English as who, whom, that, which, whose, where, or when. But truth be told, there are no exact equivalents for these terms; see the table below for possible translations, according to part of speech. It is important to know that in French, relative pronouns are required, whereas in English, they are sometimes optional and might be deleted if the sentence is clear without them.

Functions and Possible Meanings of Relative Pronouns

Qui and que are the most often confused relative pronouns, probably because French students are taught at first that qui means "who" and que means "that" or "what." In fact, this is not always the case. The choice between qui and que as a relative pronoun has nothing to do with the meaning in English, and everything to do with how the word is used; that is, what part of the sentence it is replacing.

If you come across ce que, ce qui, ce dont, and quoi, you should know that these are indefinite relative pronouns, which function differently.

Additional Resources 

Relative pronouns
Pronoun
Conjunction
Subordinate clause