'Aller,' 'Devoir,' 'Faire' and Other French Semi-Auxiliary Verbs

Like 'avoir' and 'être,' semi-auxiliary verbs are conjugated.

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The most common auxiliary verbs are avoir and être; these are the conjugated verbs that stand in front of another verb in compound tenses to indicate mood and tense. In addition to these two, French has a number of semi-auxiliary verbs, which are conjugated in order to express various nuances of time, mood or aspect and are followed by an infinitive. Some semi-auxiliary verbs are equivalent to modal verbs in English and some are verbs of perception. Here are uses and meanings of some frequently used French semi-auxiliary verbs.


In present or imperfect tense; means "to be going to"

   Je vais étudier. > I'm going to study.

   J'allais étudier. > I was going to study.

In any tense; means "to go to/and"

   Va chercher les clés. > Go and look for the keys.

   Je suis allé voir mon frère. > I went to see my brother.

In any tense; used to emphasize the verb that follows

   Je n'irai pas répondre à cela. > I'm not going to dignify that with a response.

   Je vais te dire une chose. > Let me tell you something.


In any tense except conditional and past conditional; indicates obligation or necessity

   J'ai dû partir. > I had to leave.

   Tu dois manger. > You must eat.

In conditional > "should"; in past conditional > "should have"

   Je devrais partir. > I should leave.

   Il aurait dû nous aider. > He should have helped us.


Indicates that something almost happened

   Il a failli tomber. > He almost fell.

   J'ai failli rater l'examen. > I nearly failed the test.


Causative construction: to make something happen, have something done, make someone do something

   J'ai fait laver la voiture. > I had the car washed.

   Il me fait étudier. > He's making me study.


To let something happen, let someone do something

   Vas-tu me laisser sortir ? > Are you going to let me go out?

   Laisse-moi le faire. > Let me do it.


Followed by optional de; indicates that something was about to happen or nearly happened

   J'ai manqué (de) mourir. > I almost died.

   Elle a manqué (de) pleurer. > She nearly cried.


To appear/seem to

   Ça paraît être une erreur. > That appears to be an error.

    Il paraissait être malade. > He seemed to be sick.


To leave in order to, to go to

   Peux-tu partir acheter du pain ? > Could you go out and buy some bread?

   Il est parti étudier en Italie. > He went to study in Italy.


To call/drop in on, call for, to go to

   Passe me chercher demain. > Come pick me up tomorrow.

   Il va passer voir ses amis. > He's going to drop in on his friends.


Can, may, might, to be able to

   Je peux vous aider. > I can help you.

   Il peut être prêt. > He might be ready.


To know how to

   Sais-tu nager ? > Do you know how to swim?

   Je ne sais pas lire. > I don't know how to read.


To seem/appear to

   Cela semble indiquer que… > That seems to indicate that…

   La machine semble fonctionner. > The machine appears to be working.

Sortir de 

To have just done something (informal) 

   On sort de manger. > We just ate.

   Il sortait de finir. > He had just finished.


To come (in order) to

   Je suis venu aider. > I've come to help.

venir à > to happen to

   David est venu à arriver. > David happened to arrive.

venir de > to have just done something

   Je viens de me lever. > I just got up..


To want to

   Je ne veux pas lire ça. > I don't want to read that.

   Veux-tu sortir ce soir ? > Do you want to go out tonight?

When Avoir and Être Also Act as Semi-Auxiliary Verbs

Avoir à

When followed by à + infinitive, avoir means "to have to."

   Vous avez à répondre. > You have to respond.

   J'ai à étudier. > I have to study.


Être à > to be in the process of

   Es-tu à partir ? > Are you leaving?

Être censé > to be supposed to

   Je suis censé travailler. > I'm supposed to work.

Être en passe de > to be about to (usually indicates something positive)

   Je suis en passe de me marier. > I'm about to get married

Être en train de > to be in the process of, to be doing something right now

   On est en train de manger. > We're eating (right now).

Être loin de > to not be about/going to

   Je suis loin de te mentir. > I'm not about to lie to you.

Être pour > to be ready/prepared/willing to

   Je ne suis pas pour voler. > I'm not willing to steal.

Être près de > to be about to, ready to

   Es-tu près de partir ? > Are you about to leave?

Être sur le point de ? to be about to (positive or negative)

   Il est sur le point de tomber. > He's about to fall.

More Semi-Auxiliary Verbs

Any verb that can be followed by an infinitive may be a semi-auxiliary, including (but not limited to):

  • adorer > to adore doing
  • aimer > to like, love doing
  • (s')arrêter de > to stop doing
  • chercher à > to look to do
  • choisir de > to choose to do
  • continuer à/de > to continue to do
  • croire > to believe (that one) does
  • demander de > to ask to
  • désirer > to desire to
  • détester > to hate doing
  • dire (à quelqu'un) de  > to tell (someone) to do
  • s'efforcer de > to endeavor to do
  • espérer > to hope to do
  • essayer de > to try doing
  • falloir > to be necessary to do
  • hésiter à > to hesitate to do
  • interdire (à qqun) de > to forbid (someone) to do
  • penser > to be thinking of, to consider doing
  • permettre > to allow to do
  • persister à > to persist in doing
  • promettre > to promise to do
  • préférer > to prefer doing
  • refuser de > to refuse to do
  • risquer de > to risk doing, to possibly do
  • souhaiter  > to hope to do
  • tâcher de > to try doing
  • tenter de > to attempt doing
  • voir  > to see (someone) do, to see (something) done

Word Order with Semi-Auxiliary Verbs 

Semi-auxiliary verbs are used in what I call dual-verb constructions, which have a slightly different word order than compound verb tenses. Dual verb constructions consist of a conjugated semi-auxiliary verb, such as pouvoirdevoirvouloirallerespérer and promettre, followed by a second verb in the infinitive. The two verbs may or may not be joined by a preposition.

Agreement with Semi-Auxiliary Verbs

In semi-auxiliary verb constructions, any direct object belongs to the infinitive, not the semi-auxiliary verb. Therefore, the past participle never agrees with any direct object. 

It's a decision that I hated to make.
RIGHT: C'est une décision que j'ai détesté prendre.
WRONG: C'est une décision que j'ai détestée prendre.

Here are the books that I wanted to read.
RIGHT: Voici les livres que j'ai voulu lire. 
WRONG: Voici les livres que j'ai voulus lire.

However, there may be other kinds of agreement:

  1. With the subject of the sentence, if the auxiliary verb of the semi-auxiliary is être (e.g., Nous sommes venus aider.)
  2. With the subject of the infinitive