The futuro perfeito composto is the Portuguese "will have done" tense — terei feito, terá chegado, teremos acabado. In its most straightforward use, it expresses an action that will have been completed before some future moment: by the time you arrive, I will have already left. But EP has a second, more idiomatic use that catches learners off guard: the same form is one of the preferred ways to express conjecture about the past — "he must have done it," "they must have left," "she must have been angry." This second use is unusually alive in Portuguese compared to other Romance languages, and it gives the tense a double life that is worth learning carefully.
Form: future of ter + past participle
The future perfect is built from the simple future of ter plus an invariable past participle.
| Person | ter (simple future) |
|
|---|---|---|
| eu | terei | terei falado / feito |
| tu | terás | terás falado / feito |
| ele / ela / você | terá | terá falado / feito |
| nós | teremos | teremos falado / feito |
| eles / elas / vocês | terão | terão falado / feito |
No unusual accent marks in this paradigm — terei, terás, terá, teremos, terão. (The tilde on terão is part of the regular third-person plural of the simple future: -ão.) Stress falls on the final syllable of each auxiliary form: te*rei, terás, terá, teremos, terão*. The past participle, as always under ter, is invariable.
Até ao final do mês, terei escrito o relatório.
By the end of the month, I will have written the report.
Quando chegares, já terá anoitecido.
By the time you arrive, it will already have gotten dark.
Teremos acabado antes das seis.
We will have finished before six.
Use 1: Anteriority in the future
The textbook use. An action will be complete by some future reference point — either a specific time or a later event. The future perfect names the earlier-finishing event; the later anchor is usually a simple future, a future subjunctive clause, or a time adverbial.
Quando tu chegares à estação, o comboio já terá partido.
By the time you get to the station, the train will have left.
Antes do jantar, já ele terá feito os trabalhos de casa.
Before dinner, he will have finished his homework.
Em dez anos, esta cidade terá mudado completamente.
In ten years, this city will have completely changed.
Até ao fim de semana, já teremos recebido a resposta.
By the weekend, we will have received the answer.
The future anchor is often introduced by até ("by, until"), antes de / antes que ("before"), quando ("when"), or em X tempo ("in X time"). Note that when the anchor is a quando-clause, the verb in that clause sits in the future subjunctive (quando chegares, quando tu fores). The future perfect is in the main clause.
Quando tu acordares, eu já terei saído.
When you wake up, I will already have left. (future subj. 'acordares' in the when-clause; future perfect in the main)
Assim que voltares, já terá passado tudo.
As soon as you get back, everything will already have passed.
Native speakers sometimes reach for a less bookish alternative in conversation — já terei saído → já vou ter saído or just quando chegares, já saí with the preterite standing in for the future — but the future perfect is the neutral written form and is not uncommon in careful speech.
Use 2: Conjecture and probability about the past
This is where the tense goes from textbook to idiom. In EP, the future perfect is one of the standard ways to guess about what happened in the past. When you do not know for sure but you strongly suspect something, you can use terei / terás / terá / teremos / terão + participle to mean "probably did / must have done."
Ele não atende o telefone. Terá saído.
He's not answering the phone. He must have gone out.
Não respondeu ao e-mail. Terá andado muito ocupado.
She didn't reply to the email. She must have been really busy.
Terão partido sem dizer nada.
They must have left without saying anything.
Não a vejo há semanas. Terá ido de férias.
I haven't seen her for weeks. She must have gone on holiday.
This use is the past-tense counterpart of the futuro do indicativo for conjecture about the present (Onde estará ela? — "Where could she be?"). Both tenses, present and compound, can be pressed into service to express speculation. The compound form pushes the speculation into the past.
| Tense | Literal meaning | Conjecture meaning | Example |
|---|---|---|---|
| Simple future | will be | probably is / must be | Onde estará ela? (Where could she be?) |
| Future perfect | will have been | probably was / must have been | Onde terá ela estado? (Where could she have been?) |
The future-for-conjecture is a well-known feature of Romance languages. Portuguese uses it the most freely. Where a Spanish speaker might use habrá hecho only occasionally for conjecture, a Portuguese speaker uses terá feito regularly, especially in writing, journalism, and speculative speech.
Register of the conjecture use
In neutral prose and news writing, the future perfect for conjecture is entirely natural: O ministro terá reunido com os parceiros europeus ("The minister reportedly met with European partners"). In speech, it is more common in reflective or speculative tones — the kind of sentence you say with a slight frown while puzzling something out.
For more everyday conjecture in speech, Portuguese offers several softer periphrases:
- deve ter + pp — "must have done" (common spoken form)
- terá de ter + pp — "would have to have done" (stronger logical inference)
- se calhar + pp — "maybe [did]" (with a simple preterite)
- provavelmente + pp — "probably [did]"
Ele deve ter saído.
He must have gone out. (everyday speech)
Ele terá saído.
He must have gone out. (more formal, slightly bookish)
Se calhar saiu.
Maybe he went out. (casual hedge)
All three are correct and useful. Deve ter saído is the most colloquial; terá saído is the neutral written form; se calhar saiu is informal speculation.
Examples of the conjecture use in context
Because this use is idiomatic and less obvious to non-native speakers, it is worth seeing it in a range of contexts.
A Ana não está em casa. Terá ficado a trabalhar até mais tarde.
Ana's not home. She must have stayed at work late.
O cão não come há dois dias. Terá comido alguma coisa na rua.
The dog hasn't eaten for two days. He must have eaten something out in the street.
Não estão a atender. Terão ido já para o restaurante?
They're not answering. Could they have already gone to the restaurant?
O livro desapareceu da mesa. Alguém o terá levado.
The book has disappeared from the table. Someone must have taken it.
Ele terá achado que eu não o quis ver.
He must have thought I didn't want to see him.
Notice how the tense glosses naturally as "must have" in English. That is its sweet spot — a confident but not absolute inference about what happened.
The two uses in one table
It is worth stepping back and seeing both uses of the future perfect side by side.
| Use | Time frame | Meaning | Example |
|---|---|---|---|
| Anteriority in the future | Future | "will have done" | Amanhã, já terei acabado. (Tomorrow, I will have already finished.) |
| Conjecture about the past | Past | "must have done" | Ele terá acabado. (He must have finished.) |
The same form, two different times (future vs. past), disambiguated by context. If there is a future adverbial (amanhã, até sexta, em dois anos, quando chegares), the anteriority reading kicks in. If there is a present-tense anchor or nothing temporal in the sentence at all, the conjecture reading takes over.
Até amanhã já terei ligado.
By tomorrow I will have called. (future anteriority)
Ele já terá ligado. Vamos ver no telemóvel.
He must have already called. Let's check the phone. (past conjecture)
Same tense; different readings. This ambiguity almost never causes problems because context removes it instantly.
Comparison with the synonymous structures
Three structures cover overlapping meaning. Knowing when to pick each is a matter of register and nuance.
| Construction | Typical use | Register |
|---|---|---|
| terá feito | future anteriority; past conjecture | neutral / slightly formal |
| deve ter feito | past conjecture only | everyday / spoken |
| vai ter feito | future anteriority (colloquial) | informal / spoken |
| já fez | past actuality (simple preterite) | neutral — when you know for sure |
Three paraphrases of the same sentence in different registers:
Ele terá acabado o trabalho.
He must have finished the work. (future perfect — formal conjecture)
Ele deve ter acabado o trabalho.
He must have finished the work. (modal periphrasis — everyday)
Se calhar já acabou o trabalho.
Maybe he's already finished the work. (casual)
Ele acabou o trabalho.
He finished the work. (simple preterite — no hedging)
If you hear a native speaker use terá feito in conversation, the context almost always signals careful, speculative, or slightly formal tone. In everyday casual talk, deve ter feito is more common.
Passive future perfect
Like other Portuguese compound tenses, the future perfect has a passive form — ser in the future perfect plus the past participle of the main verb. Note that ser here is in its simple future, and the overall structure combines both a future auxiliary and a participle.
O projeto terá sido aprovado até ao fim do ano.
The project will have been approved by the end of the year.
O crime terá sido cometido durante a noite.
The crime must have been committed during the night. (conjecture passive)
In the passive conjecture reading, terá sido + pp is especially common in journalism and legal reporting. It is a convenient way to report an event without attributing it definitively.
The future perfect subjunctive
For completeness, EP also has a future perfect subjunctive — tiver feito, tiveres feito, tivermos feito — which is different from the future perfect indicative discussed here. The future subjunctive compound (quando tiver acabado — "when I have finished") belongs to the subjunctive system and is used in subordinate clauses projecting a future completion. It is covered on its own page within the subjunctive tree. The form is parallel: future subjunctive of ter (tiver, tiveres, tiver, tivermos, tiverem) plus past participle.
Quando tiver acabado, vou fazer uma pausa.
When I have finished, I'm going to take a break. (future subj. compound — in the subordinate clause)
Assim que tiveres chegado, telefona-me.
As soon as you have arrived, call me.
This is the subjunctive cousin of the future perfect indicative. Do not conflate them. Terei acabado is indicative; tiver acabado is subjunctive. Both exist; both carry the "will have done" shape; but they live in different clauses.
Comparison with English and Spanish
English "will have done" maps directly onto the Portuguese future perfect in its anteriority use. For conjecture, English uses "must have + pp" — a different periphrasis from the future-conjecture pattern.
| Meaning | English | Spanish | Portuguese |
|---|---|---|---|
| Future anteriority | I will have finished. | Habré terminado. | Terei acabado. |
| Past conjecture | He must have left. | Habrá salido. | Terá saído. / Deve ter saído. |
| "What could he have done?" | What could he have done? | ¿Qué habrá hecho? | Que terá ele feito? |
Spanish speakers have a useful head start here. Spanish habré/habrás/habrá + participio covers the same double duty — future anteriority and past conjecture. The only thing that changes in Portuguese is the auxiliary: swap haber for ter and you have the Portuguese form. The semantics is almost identical.
English speakers have more to adjust. The conjecture use ("terá feito" = "must have done") is not something English does with its future form — English uses "must have" instead. If you translate terá feito mechanically as "will have done," you produce strange English; the natural translation in a conjecture context is "must have done" or "probably did."
Register notes
- Anteriority use (até amanhã, terei acabado): neutral. Used freely in writing and careful speech. In casual speech, many speakers switch to vou ter acabado or just the simple future (até amanhã, acabo).
- Conjecture use (ele terá saído): slightly formal. Common in journalism, prose, and reflective speech. In everyday spoken EP, deve ter saído is the more common alternative.
- Modern EP uses ter. Haver forms (haverei feito) are archaic — see ter vs haver.
Common Mistakes
❌ Quando chegares, eu já tinha saído.
Incorrect tense — a future anchor (chegares) requires a future perfect, not a pluperfect.
✅ Quando chegares, eu já terei saído.
By the time you arrive, I will have already left.
❌ Ele terá acabado ontem.
Questionable — with a definite past adverb like ontem, use the simple preterite (acabou) or a different periphrasis.
✅ Ele acabou ontem. / Ele deve ter acabado ontem.
He finished yesterday. / He must have finished yesterday.
❌ Haverei feito até sexta.
Archaic — modern EP uses ter as the auxiliary: terei feito.
✅ Terei feito até sexta.
I will have done it by Friday.
❌ Até amanhã, já acabarei de fazer.
Redundant — 'acabar de fazer' already means 'just finished', doesn't combine cleanly with a future perfect sense. Use terei acabado directly.
✅ Até amanhã, já terei acabado.
By tomorrow, I will have already finished.
❌ Quando tiver acabado, terei chamado-te.
Confused tenses — the main clause here should be future or imperative, not future perfect. Future perfect implies an even later anchor.
✅ Quando tiver acabado, chamo-te. / Quando tiver acabado, irei chamar-te.
When I've finished, I'll call you.
Key Takeaways
- Form: simple future of ter
- past participle
- invariable participle.
- Two uses: (1) anteriority in the future ("will have done" before a future anchor), and (2) conjecture about the past ("must have done," a hedged past assertion). Context disambiguates.
- In spoken EP, deve ter + pp is the more common colloquial way to express past conjecture; terá + pp is slightly more formal / bookish.
- The future perfect subjunctive (tiver feito) is a separate tense for subordinate clauses projecting a completed future. Do not conflate with the future perfect indicative (terei feito).
- In most Romance languages the future-of-conjecture use is alive but not central; in EP it is a regular, productive construction and a hallmark of careful Portuguese prose.
- Modern EP uses ter, not haver, as the auxiliary.
For the overall system of compound tenses, see the compound tenses overview. For the simpler, non-compound future tenses, see the future overview and future of probability.
Related Topics
- Compound Tenses OverviewA2 — The complete inventory of European Portuguese compound tenses built with ter + past participle, across indicative, subjunctive, infinitive, and gerund.
- Ter vs Haver as AuxiliaryB1 — Why modern European Portuguese uses ter instead of haver in compound tenses, with the register, set expressions, and 'haver de + infinitive' left behind.
- Pretérito Perfeito Composto (Present Perfect Compound)B1 — Tenho feito — the deep dive on European Portuguese's iterative present perfect, the tense that only means 'has been doing' over a recent ongoing period.
- Pretérito Mais-que-Perfeito Composto (Compound Pluperfect)B1 — Tinha feito — the modern Portuguese pluperfect, used for past-before-past narration in both speech and writing, alongside the literary synthetic form falara.
- Future Tense OverviewA2 — Three ways to express the future in European Portuguese, from casual speech to formal writing
- Simple Future (Futuro do Presente)A2 — Formation and uses of the synthetic future tense in European Portuguese
- Future of ProbabilityB1 — Using the future tense to express conjecture about the present
- Pluperfect Subjunctive OverviewB2 — The mais-que-perfeito do conjuntivo (tivesse + past participle) is how European Portuguese talks about past events inside irrealis contexts — counterfactual regrets, sequence-of-tenses after a past main verb, and past wishes.