De after negation and quantity expressions

Elle a des amis à Paris.amis à Paris.She has friends in Paris. → She doesn't have any friends in Paris.

Under negation, when un, une, des and du, de la, de l' introduce the direct object of the verb, they all shrink down to one small word: de (or d' before a vowel). This happens with an ordinary verb like avoir, manger or boire just as much as with any other transitive verb; être is the one common exception. Quantity words like beaucoup de and un peu de use that same de, negated or not.

Quick shortcut: negated verb + indefinite/partitive direct object → de / d' (être stays an exception). beaucoup, un peu, assez... + noun → also de / d', negation or not.

From un/une/des and du/de la to plain de

Under negation, the indefinite article (un, une, des) and the partitive article (du, de la, de l') both shrink to de when they introduce the direct object of the verb — with avoir just as with manger or boire:

• J'ai un chat. → Je n'ai pas de chat. (I have a cat. → I don't have a cat.)
• Elle mange des légumes. → Elle ne mange pas de légumes. (She eats vegetables. → She doesn't eat vegetables.)
• Je bois du café. → Je ne bois pas de café. (I drink coffee. → I don't drink coffee.)
• *Il boit **de l'*eau. → *Il ne boit **pas d'*eau. (He drinks water. → He doesn't drink water.)

This is a property of that object, not of negation in general: the definite article (le, la, les) never shrinks this way — ✅ *Je **n'*aime pas le café, never ❌ Je n'aime pas de café for "I don't like coffee".

Not after être

The shrink applies to the direct object of an ordinary negated verb. After a negated être, the indefinite article stays exactly as it is, singular or plural:

• ✅ *Ce **n'*est pas un problème. (This isn't a problem.), never ❌ Ce n'est pas de problème.
• ✅ Ce ne sont pas des mensonges. (These aren't lies.), never ❌ Ce ne sont pas de mensonges.

être introduces a description or an identification rather than a direct object, so there's nothing here for the article to shrink out of.

Quantity expressions: de before an indefinite noun

Expressions of quantity — beaucoup de (a lot of), un peu de (a little), assez de (enough), trop de (too much/many), peu de (little/few)... — are followed by plain de (or d' before a vowel) when the noun after them is indefinite, whether the sentence is affirmative or negative:

• J'ai beaucoup de travail. (I have a lot of work.)
• Il n'y a pas beaucoup de temps. (There isn't much time.)
• *Nous avons **assez d'*argent. (We have enough money.)

This looks identical to the negation shrink, but it's a different construction: there was never an article there to shrink in the first place — de is simply the fixed linking word these quantity expressions take before an indefinite noun. When the noun is instead a specific, already-known group, de combines with les into des, with a different meaning: beaucoup des amis présents means "many of the friends who were there," not "I have a lot of friends."

When the article comes back

Under contrast or emphasis, the indefinite article can reappear even after a negated verb — this is a marked, contrastive use, not the everyday neutral pattern:

• Je n'ai pas un ami dans cette ville, j'en ai dix ! (I don't have one friend in this city, I have ten!)

In an ordinary negative statement, de is the usual choice.

Common mistakes

• ❌ Je n'ai pas un chien. → ✅ Je n'ai pas de chien. (plain negation, no contrast)
• ❌ Je n'ai pas de amis. → ✅ *Je n'ai **pas d'*amis. (de elides to d' before a vowel)
• ❌ Ce n'est pas de problème. → ✅ *Ce **n'*est pas un problème. (the article stays after être)
• ❌ J'ai beaucoup des amis. → ✅ *J'ai **beaucoup d'*amis. (for an indefinite quantity — beaucoup des amis would mean "many of a specific, known group of friends")

Quick check

Fill the gap with de, d', or the untouched article.

1. Elle a un vélo. → Elle n'a pas ____ vélo.
2. Ce n'est pas ____ problème. (keep the article)
3. Nous buvons du thé. → Nous ne buvons pas ____ thé.
4. J'ai ____ amis ici. (a lot of)
5. Il y a des places. → Il n'y a pas ____ places.

Key takeaways

• When they're the direct object of a negated verb, un / une / des and du / de la / de l' all shrink to de (d' before a vowel).
• The definite article (le / la / les) never shrinks this way, and the indefinite article stays unchanged after a negated être.
• Quantity expressions (beaucoup de, un peu de, assez de...) use de before an indefinite noun, negated or not — there was no article to shrink from in the first place.
• The article can come back under contrast or emphasis (pas un ami), but that's a marked use, not the everyday pattern.