qui
who
which
that (subject of a relative clause)
C'est le mec qui m'a envoyé un message.
It's the guy who sent me a message.
who
whom
Tu parles à qui ?
Who are you talking to?
Notes
GENERAL INFO
Qui means "who" or "which." It functions as a relative pronoun (introducing a clause) or an interrogative pronoun (asking a question). It always refers to the *subject* of the verb.
USAGE
As a relative pronoun, qui replaces the subject: "C'est l'homme qui a parlé." (It's the man *who* spoke.)
As an interrogative pronoun: "Qui est là?" (*Who* is there?)
It can follow prepositions: "Pour qui?" (For *whom*?)
TRAPS
Do not confuse qui with "que." Qui is always the *subject* (who/which *does* the action), while "que" is the *direct object* (who/which *receives* the action).
Qui can refer to both people and things when used as a relative pronoun.
