Model Auxiliares and Object Pronouns
A modal verb is a verb that qualifies an action with regard to its desirability, its necessity, its possibility or its futurity.
vouloir (to want), pouvoir (can/to be able to), and devoir (must/ to have to), when used as a modal verb before a second verb, the second verb will be in the infinitive form.
Ex: Je dois aller. (I must go.)
A direct object is an object which is acted on directly by verb, without being mediated by a preposition.
Ex: Elle met ses chaussures. (She puts on her shoes.)
Direct objects can be replaced by direct object pronouns (me, te, le, la, nous, vous, les), which will agree in number and gender with the noun they replace.
Ex: Elle les met.
Vouloir followed by an infinitive expresses desire, will, or wish
Ex: Tu veux ouvir les fenêtres? (You want to open the windows?)
Object pronouns both direct and indirect are placed after the model verb but before the infinitive.
Oui, je veux les ouvrir.
Pouvoir followed by an infinitive expresses possibility, capacity, or permission.
Tu peux ouvrir la fenêtre?
non, je ne veux pas l'ouvrir
An indirect object is an object of the preposition à. Indirect objects can be replaced by an indirect object pronoun (me, te, se, lui, nous, vous, leur, y).
Ex: Nous devons écrire au commandant or;
Nous devons lui écrire
Devoir followed by an infinitive expresses obligation, or necessity.
Ex: Tu dois parler au commandant?
Non, je ne dois pas lui parler.
The verb falloir is only ever used in the third person singular: Il faut.
You will never see je faux or nous fallons.
Depending on context, it can express either necessity or obligation.
When you use il faut, you are talking about a general rule, or a general statement that applies to people.
It can mean you must (in general), we (people) must, or one must OR you need (in general), we (people) need, or one needs.
Il faut can be followed by a verb in the infinitive or a noun:
Il faut + infinitive = to need to (do something) OR must / to have to [do something]
- Il faut + noun = to need (something)
Ex: Quand on a un test, il faut étudier.