French Contractions Au, Du, Aux, Des: Rules, Examples, and Practice

French Contractions Au, Du, Aux, Des: Rules, Explanations, and Examples

When learning French, you quickly realize that the language prioritizes musicality and rhythm. To prevent jarring vowel sounds—known in linguistics as hiatus—French relies on contracted articles (les articles contractés).

Understanding how to use au, du, aux, and des is one of the quickest ways to transition from beginner phrasing to natural, authentic French. In this comprehensive guide, we will break down the mechanics, exceptions, and nuances of these contractions.

What Exactly Are French Contractions?

In French grammar, a contraction is the mandatory merger of a preposition (à or de) with the definite article (le or les).

Unlike English contractions (such as don't or they're), which are informal and optional, French contracted articles are grammatically mandatory in both spoken and written formal French. Leaving them uncontracted is considered a clear grammatical mistake.

• Incorrect: Je téléphone à le docteur.
• Correct: Je téléphone au docteur. (I am calling the doctor.)

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1. Contractions with the Preposition « À »

The preposition à generally translates to to, at, or in depending on context. It merges with masculine singular and plural definite articles:

à + le = AU

• Je vais au supermarché. (I am going to the supermarket.)
• Il joue au tennis le samedi. (He plays tennis on Saturdays.)

When « à » meets the masculine singular article « le », they contract into au.

à + les = AUX

• Elle s'adresse aux étudiants. (She is addressing the students.)
• Nous partons en vacances aux Antilles. (We are going on holiday to the West Indies.)

When « à » meets the plural article « les » (masculine or feminine), they merge into aux (pronounced /o/, with a liaison /z/ before vowels).

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2. Contractions with the Preposition « De »

The preposition de conveys origin, possession, or composition (of, from, about). It undergoes identical contraction patterns:

de + le = DU

• La porte du garage est ouverte. (The garage door is open.)
• Je reviens du bureau. (I am coming back from the office.)

When « de » meets the masculine singular article « le », it becomes du.

de + les = DES

• Le professeur corrige les copies des élèves. (The teacher marks the students' papers.)
• Voici la liste des invités. (Here is the guest list.)

When « de » precedes the plural article « les », it turns into des.

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Master Summary Matrix

Use this quick-reference table to determine whether you need to contract:

Crucial Rule: When NOT to Contract

Notice two major exceptions in the chart above:

1. Feminine Singular: « à la » and « de la » remain separate words (à la plage, de la musique).

2. Elision with Vowels: Before any singular noun beginning with a vowel or mute H, elision takes precedence (à l'université, de l'hôtel).

Two Common Pitfalls to Avoid

1. Contracted Article vs. Partitive Article

• Partitive: « Je mange du fromage. » (I am eating cheese.)
• Contracted: « La clé du bureau. » (The key of the office.)

Learners are often confused because du and des also exist as partitive articles (meaning some or an unspecified quantity):

While their grammatical origins differ, their forms are identical. Knowing the difference helps your syntactic awareness, but the spelling remains the same!

2. Object Pronouns vs. Definite Articles

• « J'ai oublié de le prévenir. » (I forgot to warn him.)

Do not contract when « le » or « les » is an object pronoun placed before a verb: Here, le means him (pronoun), not the (article). Therefore, writing du prévenir is strictly incorrect.

Quick Practice Exercise

Fill in the blanks with au, du, aux, or des:

1. Lucas donne un cours ____ enfants.

2. Nous rentrons tout juste ____ cinéma.

3. C'est l'anniversaire ____ père de Thomas.

4. Vous voyagez souvent ____ Pays-Bas ?

Answer Key

1. aux (à + les enfants)

2. du (de + le cinéma)

3. du (de + le père)

4. aux (à + les Pays-Bas)

Mastering these contractions will immediately clarify your French writing and boost your conversational confidence.