Latin had a synthetic future, formed by various allomorphs of a verbal suffix, as in canta-b-o (sing-FUT-1.SG) ‘I will sing’. It is not preserved in any Romance language. Instead Vulgar Latin avails itself of a periphrasis which puts the full verb into the infinitive und combines this with a conjugated form of the verb habere ‘have’. This combination is productive in Late Latin and first has a debitive sense, as in .

In one use of this construction, conjugation of the auxiliary is limited to present indicative active, as in .

By grammaticalization, the debitive modal component is lost and only the future meaning remains. Thus, this periphrastic construction takes on the meaning ‘I will sing’. The auxiliary loses its independence and becomes first an enclitic, as .

In the next step, the new future auxiliary becomes a verbal suffix, as in Span. cantaré (sing:FUT:1.SG) ‘I will sing’ and French chanterai id. Thus, the Romance synthetic future renews the Latin synthetic future.

This is one of the most typical examples of grammaticalization, which is why it is mentioned throughout the specialized literature. As will be seen in the section on the grammaticalization parameters, it displays changes on all of them.