Auxiliairies and conjugation

Auxiliaries

In French, there are two auxiliaries: "avoir" and "être". These two verbs do not belong to any group because their role in the conjugation is different. That's why they are classified among the auxiliaries.

Indeed, they can be used as a verb in their own right. "Être" then has the sense of existing (Et la lumière fut!) or it can introduce an attribute (Il est fort). As for "avoir", it is used in the sense to possess : j'ai une voiture.

But "être" and "avoir" also have an auxiliary role, that is to say that they serve to constitute certain forms of the conjugation of another verb. They allow to express all the notions related to the active or passive voice and to the compound forms : je suis venu quand il a dansé.

Semi-auxiliaries

Seven verbs are usually defined as semi-auxiliary. They are aller, venir, devoir, pouvoir, savoir, vouloir et faire. It is not strictly speaking a group in its own right but rather verbs which, when combined with another verb in the infinitive or the gerund, may lose their primary meaning to bring nuances into a sentence.

Semi-auxiliaries can be grouped into three categories:

		"aller" and "venir" : when followed by an infinitive, they are used to modify the temporary value. We speak of temporal verbal paraphrase. We thus obtain the near future (je vais partir) and near past (je viens de partir)
		"devoir", "pouvoir", "savoir" and "vouloir" : these verbs serve to "modalize" the verb to the infinitive that follows it. We speak of modal verbal paraphrase. - devoir indicates the necessity and sometimes the probability : je dois travailler - pouvoir indicates the possibility : il ne peut pas écrire - savoir indicates the competency : il sait lire - vouloir indicates the will : il veut partir en voyage
		"faire" : when followed by an infinitive, modify the meaning that follows it to signify that the action is not made by the subject but by someone else. We speak of verbal paraphrase factitive. Here is an example of this kind of construction : il fait relire ses œuvres.
		"se faire" : to the pronominal form followed by an infinitive, to give a passive meaning to a sentence. The subject undergoes the action. We speak of passive verbal paraphrase. Here is an example of this kind of construction: il s'est fait renvoyer de l'école.