In french, why is this sentence written with des and not les see below for what i mean.?

Question

Le professeur donne des devoirs tres difficiles~
why not say this:
Le professeur donne les devoirs tres difficiles.

The top sentence is from my french text book called "et vous" and the second is what I am asking.

de + le = du
de + la = de la
de + l' = de l'
de + les = des

but the is used to indicate possession is the examples in my book. what else is des used for in the sentences i stated on top.

Answer 1

I can't read French anymore, but the reason is this...if you say le or les or la, you mean all of it. For instance if you want sugar, you say du sucre, not le sucre. Du meaning some of the sugar. Le meaning all of the sugar that exists. I haven't taken French since 1971, but I remember that because Sr. Marie Clothilde drummed it into my head.

Answer 2

all of this are articles . DES can be observe as an exageration of LES ; Like Much and too much .
example the teacher give 3 homeworks (plural form because many ;but a lazy student instead of using les devoirs will say des devoirs).
de+le=of the(masculin related to male for example du patron=of the boss who is a man ;a lady is patonne)
de+la=of the(feminin related to female for ex....de la femme =of the lady
de+l' =de l' goes generally for things example de l'hotel =of the hotel
de+les=des use for plurals forms of of the=des commandes de ce vehicule =of comands of this vehicule
de itself in some sentences can be observe as des example de belleS routes= beautiful roads