French uses a special category of article — the partitive article — to talk about an unspecified quantity of something, roughly equivalent to English 'some' or 'any', but far more grammatically required. The forms are du (masculine singular: du pain, 'some bread'), de la (feminine singular: de la confiture, 'some jam'), de l' (before a vowel sound, either gender: de l'eau, 'some water'), and des (plural: des pommes, 'some apples'). English speakers can freely drop 'some' ('I eat bread' sounds perfectly natural), but French cannot drop the partitive article in equivalent sentences — 'Je mange pain' is simply ungrammatical. You must say 'Je mange du pain.'
The trickiest rule to internalize is what happens after a negation: in a negative sentence, du/de la/de l'/des all collapse to a single word, de (or d' before a vowel), regardless of the noun's gender or number. 'J'ai du fromage' (I have some cheese) becomes 'Je n'ai pas de fromage' (I don't have any cheese) — not 'pas du fromage'. This 'de after negation' rule also applies to indefinite articles (un/une/des) in most cases: 'J'ai un frère' → 'Je n'ai pas de frère.'
It's also important to distinguish the partitive article from the definite article, since both du/de la/des can look identical to contractions of 'de + le/la/les' used with expressions of preference. Compare 'Je mange du fromage' (I'm eating some cheese — partitive, an unspecified amount) with 'J'aime le fromage' (I like cheese — definite article, referring to cheese as a general category, not a quantity). Verbs of liking/loving/preferring (aimer, adorer, détester, préférer) normally take the definite article because you're expressing an opinion about the whole category, not consuming a portion of it.
Exemples
Je voudrais du pain, s'il vous plaît.
I would like some bread, please.
Masculine partitive 'du' — cannot be omitted the way English drops 'some'.
Elle boit de l'eau tous les jours.
She drinks water every day.
'De l'' before the vowel sound of 'eau'.
Nous mangeons de la soupe.
We are eating (some) soup.
Feminine singular partitive 'de la'.
Il y a des fruits sur la table.
There is some fruit on the table.
Plural partitive 'des'.
Je ne mange pas de viande.
I don't eat meat.
After negation, 'de la viande' becomes just 'de'.
Tu veux du café ou du thé ?
Do you want coffee or tea?
Je n'ai pas d'argent.
I don't have any money.
'De' elides to "d'" before the vowel sound of 'argent'.
J'aime le chocolat, mais je mange rarement du chocolat.
I like chocolate, but I rarely eat (any) chocolate.
Contrasts the definite article (general category) with the partitive (an actual portion).
Ils achètent des légumes au marché.
They buy vegetables at the market.
Il ne boit jamais de vin.
He never drinks wine.
'Jamais' is another negation trigger that reduces the partitive to 'de'.
Erreurs fréquentes
- Omitting the partitive article entirely, saying 'Je mange pain' instead of 'Je mange du pain', by analogy with English which allows dropping 'some'.
- Keeping du/de la/des after a negation instead of collapsing them to 'de' (saying 'Je ne mange pas du pain' instead of the correct 'Je ne mange pas de pain').
- Confusing the partitive article with the definite article after verbs of preference, e.g. saying 'J'aime du chocolat' when expressing a general like/dislike should use 'J'aime le chocolat'.
- Forgetting gender agreement on the partitive itself (using 'du' with a feminine noun like 'du confiture' instead of 'de la confiture').
Pourquoi ça trompe les anglophones
- English 'some' is optional and can vanish without changing grammaticality ('I eat bread' vs. 'I eat some bread' are both fine), so English speakers don't expect an article to be mandatory here.
- The de-after-negation collapse rule (du/de la/des → de) is a French-specific transformation that doesn't correspond to any pattern in English negation.
- English uses the same bare noun for both 'I like chocolate in general' and 'I'm eating some chocolate right now', while French forces a grammatical distinction (le vs. du) that English speakers aren't used to tracking.