Learn Hardcore Portuguese (Brazil): Quando eu terminar o relatório, vou descansar.

Do not use vou + infinitive
Do not use the simple future (terminarei)
You use the future subjunctive: terminar (the form happens to look like the infinitive here).

So:

Quando eu terminar o relatório, vou descansar. ✅
Quando eu vou terminar o relatório, vou descansar. ❌ (sounds wrong/foreign)

English uses “when + will” in meaning, but Portuguese avoids “quando + vou / quando + futuro simples” in this kind of clause and prefers the future subjunctive.

What tense is terminar in quando eu terminar o relatório?

Here terminar is in the future subjunctive (subjuntivo futuro), not the infinitive.

It looks like the infinitive, but grammatically it’s a different form:

Infinitive: terminar = to finish
Future subjunctive (1st person singular): (quando) eu terminar = when I finish (in the future, conditional on something)

Other persons in the future subjunctive:

quando eu terminar
quando você / ele / ela terminar
quando nós terminarmos
quando vocês / eles / elas terminarem

Why do we use the subjunctive here at all?

The subjunctive in Portuguese is used for:

Uncertain, hypothetical, or not-yet-real actions
Often introduced by words like quando, se, enquanto, depois que, assim que, etc., when they refer to the future

In Quando eu terminar o relatório, vou descansar, the action of finishing the report:

Is in the future
Has not happened yet
Is a condition for what comes next

That’s exactly the situation where Portuguese uses the future subjunctive instead of a normal “future tense” form in this clause.

Could I say Quando eu termino o relatório, vou descansar instead?

You can, but it changes the meaning.

Quando eu terminar o relatório, vou descansar.
= When I finish the report (this particular future event), I will rest.
Quando eu termino o relatório, eu descanso.
= When(ever) I finish the report, I rest.
This sounds like a habitual or general statement: every time I finish, I rest.

So:

For a specific future occasion: use quando + future subjunctive (quando eu terminar).
For a habit or routine: use quando + present indicative (quando eu termino).

Could I also say Depois que eu terminar o relatório, vou descansar? Is it the same?

Yes, that’s natural, and the grammar is the same:

Depois que eu terminar o relatório, vou descansar.

You still use the future subjunctive (terminar) because you’re talking about a future event that hasn’t happened yet.

Subtle difference:

Quando = when (focuses on the moment it happens)
Depois que = after (focuses on the fact that the finishing is completed before the next action)

In many contexts, both are possible and very close in meaning.

Why is it vou descansar instead of descansarei?

Modern Brazilian Portuguese strongly prefers:

ir (present) + infinitive to talk about the future:
- vou descansar = I’m going to rest / I will rest

The simple future (descansarei) exists but is:

More formal, literary, or used for emphasis
Less common in everyday spoken Brazilian Portuguese

So:

Quando eu terminar o relatório, vou descansar. ✅ (most natural in speech)
Quando eu terminar o relatório, descansarei. ✅ (correct, more formal/bookish)

Can I drop the eu and just say Quando terminar o relatório, vou descansar?

Yes, that’s completely natural and very common:

Quando terminar o relatório, vou descansar.

Portuguese often omits subject pronouns when the verb form makes the subject clear. Here, in context, it will usually be understood that you are the one finishing the report.

You’d keep the pronoun eu if you want to:

Emphasize “I, specifically”
Avoid ambiguity if there are several possible subjects in the context

Why is it o relatório and not meu relatório?

Both are possible; o relatório is just a neutral way to say “the report” and often implies “the report I’m working on”:

Quando eu terminar o relatório, vou descansar.
= When I finish the report (the one we both know about), I’ll rest.

If you want to make it explicit that it’s your report:

Quando eu terminar o meu relatório, vou descansar.

Choice depends on context:

If it’s obvious which report, o relatório is perfect and more concise.
If it could be confused with someone else’s, you might say meu relatório.

Is there any difference between Quando eu terminar o relatório, vou descansar and Vou descansar quando eu terminar o relatório?

Grammatically and in meaning, no real difference. Both are correct:

Quando eu terminar o relatório, vou descansar.
Vou descansar quando eu terminar o relatório.

The word order changes what you emphasize slightly:

Starting with Quando eu terminar o relatório gives more weight to the condition.
Starting with Vou descansar highlights the resting.

In Portuguese, both orders sound natural.

Why is there a comma in Quando eu terminar o relatório, vou descansar?

The comma is mostly for clarity and rhythm:

When the dependent clause (the part with quando) comes first, you normally put a comma before the main clause:
- Quando eu terminar o relatório, vou descansar.
When the main clause comes first, the comma is usually omitted:
- Vou descansar quando eu terminar o relatório.

This is a general punctuation pattern in Portuguese, not specific to this sentence.

How do you pronounce relatório, and what does the accent mark do?

Relatório is pronounced approximately:

heh-lah-TÓ-ryo (in Brazilian Portuguese)

Details:

The á in relatório is stressed: re-la-TÓ-rio
The accent mark (´) shows where the stress falls and that the vowel is open.
The t is like English t, not like ch.
The final -rio is usually one syllable, sounding like ryo (with a light y sound).

The accent helps you avoid mis-stressing it as “re-LA-to-rio” or something similar.

Can I say Quando eu tiver terminado o relatório, vou descansar? What’s the difference?

Yes, that’s correct but more formal and a bit more emphatic:

Quando eu terminar o relatório, vou descansar.
= When I finish the report, I’ll rest. (normal, everyday)
Quando eu tiver terminado o relatório, vou descansar.
= When I have finished the report, I’ll rest. (focuses more on the state of “having it done”)

Tiver terminado is the future perfect subjunctive. It emphasizes the completion of the action before the next one more strongly, similar to English “when I have finished” vs “when I finish”.

In everyday Brazilian speech, quando eu terminar is much more common.

If I change the subject to você, what happens to terminar?

In this sentence, the future subjunctive form for eu and você is the same:

Quando você terminar o relatório, vai descansar.
(When you finish the report, you will rest.)

Forms with different subjects:

Quando eu terminar o relatório…
Quando você / ele / ela terminar o relatório…
Quando nós terminarmos o relatório…
Quando vocês / eles / elas terminarem o relatório…

Is Quando eu tiver terminado o relatório, vou descansar more “correct” than Quando eu terminar o relatório, vou descansar?

No. Both are fully correct; they just have slightly different style and nuance:

Quando eu terminar o relatório, vou descansar.
– Standard, neutral, most common in speech and writing.
Quando eu tiver terminado o relatório, vou descansar.
– More formal, more explicit about the action being fully completed before resting.

In everyday Brazilian Portuguese, quando eu terminar is usually preferred.