Are there any languages with a plufuture for tense sequencing?

Question

(I admit a Romance bias in asking this question, perhaps expressing what I'm looking for is quite common in other families)

After answering a question recently on the Spanish SE on tense sequencing, I got to wondering. Many languages make frequent use of a pluperfect, either via direct formation or auxiliar verbs.

While I suppose many languages could form it by combining two ways of talking about the future (English: "I will be going to V.", Asturian: "Diré V."), they tend not to be used that often, rather being substituted by the standard future forms supplemented with adverbs to indicate the sequencing.

Are there any languages/language families that dictate future tense sequencing as strictly as past tense sequencing such that they either require or regularly use a plufuture?

Edit: Some overly simple examples based on the verb swim , but I think it will make sense even if there's a few nits that could be picked:

First, the three basic time frames (past, present, future)

• David swam, John swims, and Mary will swim.
• David nadou, João nada e Maria nadará.

But, if we shift the point of reference to the past, the verb forms all shift.

• Yesterday David had (already) swum, John swam, and Mary would swim.
• Ontem David (já) nadara, João nadou e Maria nadaria.

But, let's say instead of shifting the reference backwards, we shift forward:

• Tomorrow David will have swum, John will swim, and (then) Mary will swim.
• Amanhã David haverá nadado, João nadará e (depois) Maria nadará.

Notice that expressing John and Mary's swimming use the same verb constructions. The only common way to show that Mary's future swimming comes after John's future swimming is to use an adverb, although theoretically I suppose the following would be possible:

• Tomorrow David will have swum, John will swim, and Mary will go to swim.
• Amanhã David haverá nadado, João nadará e María ^?irá nadar.

Except that the meaning of go here for me curiously shifts from its future sense meaning to the movement sense, causing to to take its "for the purpose of". I'm not 100% certain of the grammaticality of the Portuguese one, although it's Spanish counterpart irá a nadar would have the same interpretation as the English.

So what I'm looking for would be a language where, in order to properly express the future-shifted version, the John and Mary's will swim would be constructed differently in an effectively obligatory nature.

Answer 1

In Reichenbach's scheme of eventuality, reference point and speech point, the "future of the future" describes where the eventuality is after the reference point, which is after the speech point (S - R - E). This "posterior future" makes the referred event the "act of preparation" rather than the act or event itself.

The classic example is the Latin abiturus ero, which in English is (idiomatically) translated as "I shall be one of those who will leave". I've also seen the translation "I shall be going to leave", which is a little more compact but feels a lot less natural. In some English grammar textbooks this is named the "future prospective", but I agree that this (currently!) looks and feels like a purpose clause.

I've seen statements that the "future of the future" or "posterior future" is "not attested in natural languages". I personally think it's just hard to disentangle them from other semantic colourings, much as all future tense-based forms are.

Kannada reportedly has an auxiliary verb construction with +posterior and +future, and the third person neuter form is apparently quite frequent. But it has an obligatory force to its meaning: one needs to go.

Answer 2

German has two future tenses (called 'Futur I and II' in popular grammars), and if they are used together, this comes close to what you're asking for:

German: Wenn ich gegessen haben werde, werde ich satt sein.

Gloss: When I eaten-past-partcpl have will, will I not-hungry be.

Tenses: ............. Futur II ..............................Futur I

English: When I will have eaten, I will not be hungry any more.

However, German Futur II does not express an action taking place after the action expressed by Futur I. Instead, Futur II expresses an action taking place in the future, but before another action expressed by Futur I. In this respect it is similar to the pluperfect, which expresses an action that took place before another action expressed by the perfect/past tense. But the relation between Futur II and Futur I is not a mirror-image of the relation between pluperfect and perfect.

Also note that Futur I is the unmarked tense here. Used on its own, it just refers to an action taking place in the future.