French Auxiliary Verbs: How to Master Être and Avoir (Rules & Conjugation)

When learning French, understanding auxiliary verbs (les verbes auxiliaires) is one of the most critical milestones you will reach. Auxiliary verbs—also known as "helping verbs"—are essential building blocks used to form compound tenses such as the passé composé, plus-que-parfait, and futur antérieur.

In French, there are only two main auxiliary verbs: avoir (to have) and être (to be). While the concept sounds straightforward, knowing which verb to use and how to handle past participle agreement is notorious for tripping up learners.

In this complete guide by my-french.com, we will break down the rules, conjugation tables, and practical examples to help you master French auxiliary verbs once and for all.

1. What Are French Auxiliary Verbs?

An auxiliary verb combines with a past participle (participe passé) of a main verb to form compound tenses:

$$\text{Subject} + \text{Auxiliary (conjugated)} + \text{Past Participle}$$

  • J'ai mangé une pomme. (I ate an apple. Auxiliary: avoir)
  • Elle est partie hier. (She left yesterday. Auxiliary: être)

Beyond compound tenses, être also serves to construct the passive voice in French (e.g., La maison est construite par l'architecte).

2. Present Tense Review: Être vs. Avoir

Because compound tenses depend on the present tense of auxiliary verbs, memorizing these two irregular verbs is mandatory:

3. When to Use "Avoir"

Subject Pronoun Avoir (to have) Être (to be)
Je / J' ai suis
Tu as es
Il / Elle / On a est
Nous avons sommes
Vous avez êtes
Ils / Elles ont sont

Avoir is the default auxiliary in French. Roughly 90% of all French verbs form their compound tenses with avoir, including all transitive verbs (verbs taking a direct object).

The Past Participle Agreement Rule with Avoir

  • Les garçons ont parlé. (The boys spoke — no "s" added to parlé).
  • Les filles ont dormi. (The girls slept — no "e" or "s" added to dormi).

    • By default, the past participle used with avoir does not agree with the subject:

  • J'ai vu ces photos. (Direct object ces photos is after the verb -> no agreement).
  • Ces photos ? Je les ai vues. (The direct object pronoun les comes before -> feminine plural agreement: +es).

    • The Crucial Exception: The past participle agrees in gender (+e) and number (+s) with the Direct Object (COD) only when that direct object is placed before the auxiliary verb:

    4. When to Use "Être"

While less common than avoir, être is used in two critical grammatical contexts:

A. Verbs of Movement and State (DR MRS VANDERTRAMP)

  • Devenir (to become)
  • Revenir (to come back)
  • Monter (to go up)
  • Rester (to stay)
  • Sortir (to go out)
  • Venir (to come)
  • Aller (to go)
  • Naître (to be born)
  • Descendre (to go down)
  • Entrer (to enter)
  • Rentrer (to return home)
  • Tomber (to fall)
  • Retourner (to return)
  • Arriver (to arrive)
  • Mourir (to die)
  • Partir (to leave)

    • A specific group of intransitive verbs expressing movement or life transitions takes être:

    B. All Reflexive / Pronominal Verbs

  • Se réveiller -> Je me suis réveillé(e).
  • Se laver -> Nous nous sommes lavé(e)s.

    • Any verb preceded by the reflexive pronoun se uses être in compound tenses:

    Agreement Rule with Être

  • Marc est venu. (Masculine singular -> standard form)
  • Sophie est venue. (Feminine singular -> add e)
  • Marc et Sophie sont venus. (Masculine plural -> add s)
  • Sophie et Claire sont venues. (Feminine plural -> add es)

    • With être, the past participle always agrees in gender and number with the subject:

    5. Dual Auxiliary Verbs: Être or Avoir?

  • Monter, descendre, sortir, rentrer, retourner, passer.

    • Six movement verbs can take either être or avoir depending on whether they have a direct object:

Compare these sentences:

1. No direct object (intransitive) -> Être

  • Je suis sorti. (I went out.)
  • Elle est montée dans le train. (She boarded the train.)

2. With a direct object (transitive) -> Avoir

  • J'ai sorti mon passeport. (I took out my passport.)
  • Elle a monté les valises. (She carried the luggage upstairs.)

    • Key Takeaways for French Learners

1. Use avoir by default for most verbs.

2. Use être for the DR MRS VANDERTRAMP movement verbs and all reflexive verbs.

3. Always make the past participle match the subject when using être.

4. Check whether a movement verb has a direct object before choosing between avoir and être.

Mastering French auxiliary verbs takes consistent practice. Start by writing 5 sentences with avoir and 5 with être today to solidify your grammar skills!