The Future Perfect Continuous

The Future Perfect Continuous

conjugation

The perfect future (Future Perfect) English is built with this structure: 

[SUBJECT] + Will / Shall Have Been + [GERUND WORD (-ing form)] 

Note: As we have already told in the simple future auxiliary Shall is used only for the first person singular and plural. 

To leave this structure clearer then see how the verb is conjugated to save (save):

Conjugación	Significado
I will have been saving I shall have saving	yo habré estado ahorrando
you will have been saving	tú habrás estado ahorrando
he will have been saving	él habrá estado ahorrando
we will have been saving we shall have been saving	nosotros habremos estado ahorrando
you will have been saving	vosotros habréis estado ahorrando
they will have been saving	ellos habrán estado ahorrando

As seen in the future simple personal pronouns and the auxiliary "will" can be contracted: 

I'll will ➜

Denial of Future Perfect

Denial is easily formed not by adding the adverb between the auxiliary and the verb will: 

[SUBJECT] + Will / Shall not Have Been + [GERUND WORD (-ing form)]

Conjugación	Significado
I will not have been sleeping I shall not have been sleeping	yo no habré estado durmiendo
you will not have been sleeping	tú no habrás estado durmiendo
he/she/it will not have been sleeping	él no habrá estado durmiendo
we will not have been sleeping we shall not have been sleeping	nosotros no habremos estado durmiendo
you will not have been sleeping	vosotros no habréis estado durmiendo
they will not have been sleeping	ellos no habrán estado durmiendo

will not and will not shrink in 

Shall not Shall not contracts in

Questioning the future perfect continuous

The question is formed by simply inverting the auxiliary verb and the subject: 

Will / Shall + [SUBJECT] + Have Been [GERUND WORD]?

Conjugación	Significado
will I have been traveling? shall I have been traveling?	¿habré estado viajando?
will you have been traveling?	¿habrás estado viajando?
will he have been traveling?	¿habrá estado viajando?
will we have been traveling? shall we have been traveling?	¿habremos estado viajando?
will you have been traveling?	¿habréis estado viajando?
will they have been traveling?	¿habrán estado viajando?

Using Continuous Future Perfect

This tense is used to indicate that an event has been started in the past will continue until a time in the future. This time point has to be specified for the phrase makes sense. 

It looks easier with an example:

When I retire, I will have been working for 40 years
¿Cúando me jubile, habré estado trabajando durante 40 años