One of the first things that catches a learner’s attention in French is the tiny but tricky word de.

It appears everywhere in everyday speech, yet it often raises questions:
Why do we sometimes see de, other times du, de la, or des?
When does des turn into de — and when does it stay the same?

Understanding when to use de isn’t just about grammar. It’s about recognizing essential sentence patterns and sounding more natural when you speak or write.

In this article, we’ll go over the main situations where de is used, with clear examples and practical tips to avoid the most common mistakes and make your French smoother and more precise.

1. De after a negation

In French, in negative sentences, all partitive and indefinite articles turn into de:

– Je n’ai pas de cigarette.

This applies not only with ne… pas, but also with other negatives like ne… jamais, ne… plus, ne… aucun(e).

– M. Dupont ne boit plus de vin.

Important exception: after the verb être, the article does not change.

– Ce n’est pas du bon vin.

2. De after expressions of quantity

After expressions of quantity such as beaucoup de, peu de, assez de, trop de, combien de, you always use de.

– Nous avons beaucoup de problèmes en ce moment.

Exception: certain expressions keep des, such as la plupart des, bien des.

– La plupart des Français prennent leur vacances en août.

3. De before a plural noun with an adjective

When an adjective comes before a plural noun, des changes to de:

– Elle a fait de nombreuses observations.

If there’s no adjective, or if the adjective comes after the noun, it stays des:

– Elle a fait des observations intéressantes.

4. Don’t confuse the two des

There are actually two different des in French:

1) des = plural indefinite article

→ This one can become de (in negation, when an adjective comes before the noun…)

– Nous avons des appartements à louer. → Nous n’avons plus d’appartements à louer.

2) des = contraction of de + les

→ This one never changes.

– Vous n’avez pas parlé des nombreux problèmes qui vous accablent.

5. Special cases to remember

There are also a few fixed expressions that require de without an article. These don’t follow a general rule — they’re set phrases you just need to learn as they are.

1) With de mes/tes/ses nouvelles

– Il y a longtemps que je n’ai pas eu de ses nouvelles.

Here, de introduces the object of the conversation without adding an article — a very common idiomatic structure in everyday French.

2) After certain verbs

Some verbs require de without an article:

– Tu changes facilement d’ habitude.

These are fixed patterns: changer de + nom / se tromper de + nom.

3) In expressions like en matière de

– En matière de santé, les habitudes sont importantes.

Here de functions purely as a preposition, introducing the topic.

6. To sum up

French uses the simple form de in three main contexts:

• after negation
• after expressions of quantity
• when an adjective comes before a plural noun

Plus, remember the difference between:

• des → de (an indefinite article, which can change)
• des = de + les (a contraction, which never changes)

You don’t need to memorize every rule — with exposure and a bit of practice, these patterns will soon feel natural.

7. Want to go further?

Check out the reference sheet: “L’emploi de « de » et « des »“.

And if you’d like to build a strong foundation in French so you can master these structures with confidence, take a look at our course: Et voilà! : a clear, motivating, step-by-step program to learn French with ease.