French Passive Infinitive

Even though the French infinitive translates as "to + verb," the French infinitive sometimes needs to be preceded by a preposition. This phenomenon can be divided into two categories: verbs that must be followed by a preposition (see lesson) and the passive infinitive, which you will learn about in this lesson.
The passive infinitive occurs when a sentence is written in such a way that the infinitive has a passive, rather than active, meaning. This construction requires the preposition à. Compare these two sentences:
Je veux dire quelque chose.
J'ai quelque chose à dire.
The first sentence, "I want to say something," is active - this want is an active state of mind. The second sentence, "I have something to say," is passive: the speaker is using this construction to emphasize the "something to say," rather than the action of actually saying it. It might help to literally translate it as "I have something to be said."
The passive infinitive occurs most commonly with indefinite words, including negative indefinites. This is not a definitive list, but it should give you a good idea about when and how to use the passive infinitive.

Indefinite Pronouns

   Je cherche quelque chose à lire.
I'm looking for something to read.
En voici un autre à corriger.
Here's another one to correct.
Aimes-tu les films ? En voici plusieurs à voir.
Do you like movies? Here are several to watch.

Negative Pronouns

   Il n'y a rien à manger.
There's nothing to eat.
Elle n'en a pas une seule à partager.
She doesn't have a single one to share.

Indefinite Adjectives

   Je cherche une autre voiture à louer.
I'm looking for another car to rent.   Il regarde chaque peinture à vendre.
He looks at each painting to be sold.
Il y a maintes choses à faire demain.
There are many things to do tomorrow.

Negative Adjectives

   Je n'ai aucun argent à te prêter.
I don't have any money to loan you.
Il n'y a pas un seul ordinateur à utiliser.
There isn't a single computer to use.
Il n'a nulle sagesse à communiquer.
He has no wisdom to impart.

Indefinite Article or Number

   Il me reste une maison à vendre.
I have one house left to sell.
Elle a trouvé un chien à adopter.
She found a dog to adopt.
J'ai acheté quatre tartes à partager avec le groupe.
I bought four pies to share with the group.

Presentatives

   C'est difficile à dire.
It's hard to say.
Il y a beaucoup de choses à faire à Paris.
There are a lot of things to do in Paris.
Voici les vêtements à laver.
Here are the clothes to wash.
Note that sometimes c'est and il est must be followed by de rather than à - learn more.

Sentence Fragments

The passive infinitive may also be used in fragments:
À vendre
For sale
Maison à louer
House for rent