With partitive and indefinite articles, the de vs du, de la, des choice has to do mainly with whether the statement is affirmative or negative and whether there's an adjective in front of the noun.
1. The partitive article indicates an unknown quantity of something, usually food or drink:
Je veux du lait.
I want some milk.
Nous avons mangé de la glace.
We ate some ice cream.
2. The plural partitive article des refers to something that is uncountable but plural in French (see English singulars and French plurals):
Il a mangé des épinards.
He ate some spinach.
Peux-tu me donner des conseils ?
Could you give me some advice?
3. The plural indefinite articledes refers to more than one countable thing in an indefinite sense.
Il a des livres intéressants.
He has some interesting books.
J'ai acheté des chaussettes.
I bought some socks.
4. In a negative construction, the partitive and indefinite articles (singular and plural) change to de, usually meaning "(not) any":
Nous ne voudrions pas de lait.
We don't want any milk.
Je n'ai pas mangé de soupe.
I didn't eat any soup.
Il n'a pas de livres intéressants.
He doesn't have any interesting books.
Je n'ai pas acheté de chaussettes.
I didn't buy any socks.
Nous n'avons pas de voiture.
We don't have a car.
Exceptions
a. If the verb is être, the article remains the same:
C'est une poire, ce n'est pas une pomme.
It's a pear, it's not an apple.
C'est de la viande. - Ce n'est pas de la viande.
It's meat. - It's not meat.
b. You can keep the article in order to stress the negative aspect:
Je n'ai pas de sous - Je n'ai pas un sou.
I don't have any money - I don't have a (single) cent.
Il ne veut pas de bébé. - Il ne veut pas un bébé.
He doesn't want a baby. - He (really) doesn't want a baby.
5. When the plural indefinite or partitive article is used with an adjective that precedes a noun, des changes to de.
J'ai des amis. - J'ai de jeunes amis.
I have some friends. - I have some young friends.
(Note: J'ai un jeune ami. - I have a young friend.)
J'ai mangé des épinards. - J'ai mangé de bons épinards.
I ate some spinach. - I ate some good spinach.
(Note: J'ai mangé de la bonne sauce des épinards. - I ate some good spinach sauce.)
Test on de vs du, de la, des
1. The partitive article indicates an unknown quantity of something, usually food or drink:
Je veux du lait.
I want some milk.
Nous avons mangé de la glace.
We ate some ice cream.
2. The plural partitive article des refers to something that is uncountable but plural in French (see English singulars and French plurals):
Il a mangé des épinards.
He ate some spinach.
Peux-tu me donner des conseils ?
Could you give me some advice?
3. The plural indefinite articledes refers to more than one countable thing in an indefinite sense.
Il a des livres intéressants.
He has some interesting books.
J'ai acheté des chaussettes.
I bought some socks.
4. In a negative construction, the partitive and indefinite articles (singular and plural) change to de, usually meaning "(not) any":
Nous ne voudrions pas de lait.
We don't want any milk.
Je n'ai pas mangé de soupe.
I didn't eat any soup.
Il n'a pas de livres intéressants.
He doesn't have any interesting books.
Je n'ai pas acheté de chaussettes.
I didn't buy any socks.
Nous n'avons pas de voiture.
We don't have a car.
Exceptions
a. If the verb is être, the article remains the same:
C'est une poire, ce n'est pas une pomme.
It's a pear, it's not an apple.
C'est de la viande. - Ce n'est pas de la viande.
It's meat. - It's not meat.
b. You can keep the article in order to stress the negative aspect:
Je n'ai pas de sous - Je n'ai pas un sou.
I don't have any money - I don't have a (single) cent.
Il ne veut pas de bébé. - Il ne veut pas un bébé.
He doesn't want a baby. - He (really) doesn't want a baby.
5. When the plural indefinite or partitive article is used with an adjective that precedes a noun, des changes to de.
J'ai des amis. - J'ai de jeunes amis.
I have some friends. - I have some young friends.
(Note: J'ai un jeune ami. - I have a young friend.)
J'ai mangé des épinards. - J'ai mangé de bons épinards.
I ate some spinach. - I ate some good spinach.
(Note: J'ai mangé de la bonne sauce des épinards. - I ate some good spinach sauce.)
Test on de vs du, de la, des
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