The teacher had (made) the students sing
L'instituteur a fait chanter les élèves
Recall the causative use of faire, which is formed by faire + an infinitive. If the direct object in a causative construction is a noun (les élèves in this case), it follows the infinitive.
She had the car washed. She had it washed
Elle a fait laver la voiture. Elle l'a fait laver
If the direct object in a causative construction is an object pronoun (l' in this case), it precedes faire. Also note that the object of faire here is laver, so the past participle of faire does not agree with the preceding feminine direct object pronoun.
Have the house built. Have it built
Faites construire la maison. Faites-la construire
Note the placement of the direct objects in these (affirmative) imperative causative constructions. When the direct object is a pronoun (as in the second sentence), it follows the verb (attached with a hyphen) but precedes the infinitive.
He had the students sing the song. He had them sing it
Il a fait chanter la chanson par les élèves. Il la leur a fait chanter
Here, two pronouns are used with the causative faire. The students (those doing the action) are the indirect object, while the song being sung is the direct object. Note also that the past participle of faire is invariable when followed by an infinitive.
I am having him clean it
Je le lui fais nettoyer
Two pronouns are used in this causative construction. Recall that le/la/les should come before lui/leur when two pronouns are used.
She had the newspaper brought to her
Elle s'est fait apporter le journal
The reflexive causative indicates that the subject is having something done to or for himself/herself.
You have your hair cut
Tu te fais couper les cheveux
Note the use of the reflexive se faire in this causative construction. Also recall how the definite article is used with body parts like cheveux.
I let Marcel do his homework
Je laisse Marcel faire ses devoirs
Note how the infinitive can be used after the verb laisser. This is similar to how the infinitive is used with faire in causative constructions.
Did you let Jean eat the dessert?
Est-ce que tu as laissé Jean manger le dessert?
My parents let me play guitar
Mes parents me laissent jouer de la guitare
Note how the direct object pronoun me precedes the verb here.
I let him do it
Je le laisse le faire
There are two object pronouns here. One of them precedes the verb, while the other, which is the object of the infinitive, precedes the infinitive. In other words, the second le here refers to "it," which is the object of the infinitive faire.
We hear Paul singing
On entend chanter Paul
Just like laisser, verbs of perception can be followed by the infinitive. Verbs that can be used like this include: entendre, voir, sentir, regarder, and écouter.
We saw Maxime reading his book
Nous avons vu Maxime lire son livre
In this verb of perception + infinitive construction, the noun livre (the object of the infinitive lire) comes after the infinitive.
I see the girl eating. I see her eating
Je vois manger la fille. Je la vois manger
Note the placement of the direct object pronoun before the verb of perception.
We heard Marie sing(ing) the song. We heard her sing(ing) the song
Nous avons entendu Marie chanter la chanson. Nous l'avons entendue chanter la chanson
Note how the feminine past participle agrees with the preceding feminine object pronoun l', which replaces Marie.
They heard her singing
Ils l'ont entendue chanter
Note how the participle agrees with the preceding object pronoun, which refers to a woman singing. The woman performs the action expressed by the infinitive. In other words, she is the subject of the infinitive, which warrants participle agreement.
They heard it (the song) sung
Ils l'ont entendu chanter
Here, the participle entendu does not agree with the preceding object pronoun, which refers to a song being sung. This is because the song is actually the object of the infinitive, chanter. Participle agreement could only occur if the song were the subject of the infinitive, which is not the case.
We heard her sing(ing) the song. We heard her sing(ing) it
Nous l'avons entendue chanter la chanson. Nous l'avons entendue la chanter
Here, two object pronouns are used. The first (l') applies to the person singing, while the second (la) is the song being sung.
After visiting Paris, he went to Grenoble
Après avoir visité Paris, il est allé à Grenoble
Note the past infinitive, which is formed by pairing the infinitive of either avoir or être with a past participle. The past infinitive is used for actions that happened before other actions. Both actions are performed by the same subject.
Thank you for helping him
Merci de l'avoir aidé
In English, the more literal translation here would be "Thanks for having helped him," which is how we say it in French. Also note the object pronoun l', placed before the verb construction here.
I'm sorry for having missed you at the airport
Je suis désolé de t'avoir manqué à l'aéroport
Note the use of de after désolé -- "sorry for." Also note the object pronoun t', which precedes the past participle construction.
They're happy that they came
Ils sont contents d'être venus
Note how the past participle agrees with the subject, since the auxiliary verb is être. (A more direct English translation would have been "They're happy for having come.")
You guys wanted to (have) finish(ed) by Saturday
Vous vouliez avoir terminé avant le samedi
Here, the past infinitive modifies the main verb, vouloir.
Julie? After seeing her, we left
Julie? Après l'avoir vue, nous sommes partis
Note how the past participle vue agrees with its preceding feminine direct object.
He regrets not coming/having come
Il regrette de ne pas être venu
Note the placement of negative adverbs in the past infinitive. Ne and pas do not surround the past infinitive; instead, they both precede it.
Marie can no longer take care of her grandmother
Marie ne peut plus prendre soin de sa grand-mère
to take care of - prendre soin de. Note that an alternative is the reflexive construction s'occuper de.
I dream of a day when cancer will be cured
Je rêve d'un jour où le cancer sera guéri
to cure - guérir. Note that "to cure someone of something" is guérir quelqu'un de quelque chose. Also note how où is used instead of quand to refer to a moment in time.
Sorry to bother you
Excusez-moi de vous déranger
to bother, to disturb - déranger
I sneeze when I'm in the same room as a dog
J'éternue quand je suis dans la même pièce qu'un chien
to sneeze - éternuer
When someone sneezes, I always say "Bless you!"
Quand quelqu'un éternue, je dis toujours "À vos souhaits!"
bless you - à vos souhaits. This literally means "to your wishes." When addressing someone with whom you are more familiar, you could say à tes souhaits.