The endings of the future tense in French look very much like the forms of the auxiliary verb avoir for good reason. In late spoken Latin, the original Latin future was replaced by a verb + infinitive construction consisting of the auxiliary verb habere (ancestor of French avoir) + the infinitive. The meaning shifted from I have to go or I am to go to I will go. The forms of habere were usually placed after the infinitive in spoken Latin and eventually became fused with it, giving the forms of the future in modern French.