When do you use du, de la and des in French?
Use the partitive when you mean an unspecified amount of something — du pain is some bread. English usually leaves this out entirely, saying just bread, which is why learners omit it. French does not allow that: a noun almost always needs an article, and after a negative the partitive collapses to plain de.
French nouns need an article
This is the underlying rule and it explains most partitive errors. Where English can put a bare noun after a verb — I eat bread — French cannot. It requires du, de la, de l' or des according to gender and number.
Je mange du pain.
I eat bread.
Masculine singular.
Je bois de la bière.
I drink beer.
Feminine singular.
J'achète des pommes.
I buy apples.
Plural.
Je bois de l'eau.
I drink water.
Before a vowel.
After a negative it becomes de
In a negative sentence the partitive reduces to de regardless of gender or number. This applies to the indefinite articles un and une as well, and it is one of the most reliable rules in French — with one clear exception.
Je mange du pain. → Je ne mange pas de pain.
I don't eat bread.
J'ai des amis. → Je n'ai pas d'amis.
I don't have friends.
Ce n'est pas du pain.
That isn't bread.
The exception — after être the article survives.
After a quantity it is also de
Expressions of quantity are followed by plain de, not by the partitive. Beaucoup de, un peu de, trop de, assez de, un kilo de — all take de alone.
beaucoup de pain
a lot of bread
Not beaucoup du pain.
un peu de lait
a little milk
trop de travail
too much work
Common mistakes
Je mange pain.
Je mange du pain.
French does not allow a bare noun here. An article is required even where English omits one.
Je n'ai pas du temps.
Je n'ai pas de temps.
The partitive reduces to de after a negative.
beaucoup du monde
beaucoup de monde
Expressions of quantity take plain de, never the partitive.
Frequently asked questions
What is the difference between du and le?
Du pain is some bread, an unspecified amount. Le pain is bread in general or a specific loaf already known. J'aime le pain means I like bread as a category; je mange du pain means I am eating some now.
Why does des become de before an adjective?
In careful written French, des reduces to de before a plural adjective that precedes the noun — de belles maisons rather than des belles maisons. In ordinary speech many speakers keep des, and both are heard.
Does the negative rule ever not apply?
After être the article survives: ce n'est pas du vin, not ce n'est pas de vin. That is the exception worth memorising; everything else follows the rule.