Sortir and Partir Difference?

There are five French verbs that mean to leave: partir, s'en aller, sortir, quitter, and laisser.

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!