There are five French verbs that mean to leave: partir, s'en aller, sortir, quitter, and laisser. These all have different meanings, so how do you know which one to use? Let's find out.
Partir means to leave in a general sense - it is the opposite of arriver (to arrive). Partir is intransitive, which means that it cannot be followed by a direct object; however, it may be followed by a preposition + indefinite object (normally, the destination or point of departure):
Nous partons jeudi
We're leaving on Thursday
Ils partent de Paris
They're leaving (from) Paris
Je suis parti pour le Québec
I left for Québec
In addition, partir is a euphemism for death:
Mon mari est parti
My husband passed away
S'en aller is more or less interchangeable with partir, but it has a slightly informal nuance: to go away/off. It can also mean to retire or to die.
Ils s'en vont à Paris
They're going away to Paris
Je m'en vais, salut !
I'm off, bye!
Va t'en !
Go away!
Mon père vient de s'en aller
My father just retired (or died, depending on context)
Sortir means to go out, to get out of something, or to get something out - it is the opposite of entrer (to enter) and can be transitive or intransitive:
Je sors ce soir
I'm going out tonight
Tu dois sortir de l'eau
You have to get out of the water
Nous allons sortir en bicyclette
We're going out for a bike ride
Il doit sortir la voiture du garage
He has to get the car out of the garage
Quitter means to leave someone or something - it is transitive, meaning that it must be followed by a direct object. It often indicates a prolonged separation.
Ils quittent la France
They're leaving France
Il quitte sa femme
He's leaving his wife
The only exception to the direct object rule is when on the phone:
Ne quittez pas
Don't hang up
Laisser means to leave something in the sense of not taking it with/for oneself - it is transitive:
J'ai laissé mon sac chez Luc
I left my bag at Luc's house
Laissez-moi du gâteau !
Leave me some cake! (Leave some cake for me!)
Laisser can also mean to leave someone alone:
Laissez-moi tranquille !
Leave me alone!