Learn Hardcore Portuguese (Portugal): A tristeza às vezes volta depois do exame. - Sadness sometimes returns after the exam.

You can sometimes drop the article and just say Tristeza in special contexts (titles, slogans, poetic language), but in normal speech and writing, A tristeza sounds more complete and idiomatic.

So:

A tristeza às vezes volta depois do exame. ✅ natural, normal
Tristeza às vezes volta depois do exame. ❌ sounds odd in standard prose/speech

What is the difference between às vezes and as vezes? Why does às have an accent here?

Às vezes (with accent) and as vezes (without accent) are not the same.

às vezes – means sometimes
as vezes – literally the times (article + noun), used in other contexts

The form às is a contraction:

a (preposition “to/at”) + as (feminine plural article “the”) → às (with a grave accent)

Historically, às vezes is like saying “at the times”, which became the fixed expression “sometimes”.

In this sentence you must write:

A tristeza às vezes volta... ✅
A tristeza as vezes volta... ❌ (spelling mistake; it no longer means “sometimes”)

Where can I put às vezes in the sentence? Is Às vezes a tristeza volta depois do exame also correct?

Yes, Às vezes a tristeza volta depois do exame is also correct.

With adverbs like às vezes, Portuguese word order is flexible. All of these are grammatical:

A tristeza às vezes volta depois do exame.
Às vezes, a tristeza volta depois do exame.
A tristeza volta, às vezes, depois do exame. (more “inserted”, slightly more marked)

The most neutral and common are 1 and 2.

Putting Às vezes at the very beginning (option 2) slightly emphasizes the frequency (“Sometimes, sadness comes back...”).
Keeping it inside the sentence (A tristeza às vezes volta...) sounds very natural and is also common.

So position is flexible, but you cannot split às and vezes, and it should stay close to the verb or at the start of the clause.

Why is it volta and not voltar or volta-se?

Volta is the present tense, 3rd person singular of the verb voltar (“to return”, “to come back”):

eu volto – I come back
tu voltas – you come back
ele / ela / você volta – he / she / you (formal) comes back

In your sentence, a tristeza is the subject (3rd person singular), so the verb must be volta:

A tristeza volta... – Sadness comes back...

Why not the other forms?

voltar (infinitive) would be like saying “Sadness to come back” – not a complete sentence.
volta-se would mean “it comes back by itself” or could have a reflexive/passive nuance. It’s not necessary here and would sound strange. The simple volta is the normal, natural choice.

Which tense is volta? Could I also say voltará or voltou?

Volta is present tense (presente do indicativo). Here it describes something that happens generally or repeatedly:

A tristeza às vezes volta depois do exame.
→ “Sadness sometimes comes back after the exam (in general).”

You can change the tense to change the meaning:

A tristeza às vezes voltou depois do exame.
→ past: “Sadness sometimes came back after the exam” (talking about a past period).
A tristeza às vezes voltará depois do exame.
→ future: “Sadness will sometimes come back after the exam” (possible, but a bit formal/less common in speech; often people would use vai voltar instead: vai voltar = “is going to come back”).

So volta here expresses a habitual/general fact, not a single, one-time event.

What exactly does depois do exame mean? Why is it do and not de or da?

Depois do exame literally means “after the exam”.

It is made of:

depois de – after
o exame – the exam

In Portuguese, de + o contracts to do:

de + o → do (masculine singular)
de + a → da (feminine singular)
de + os → dos (masculine plural)
de + as → das (feminine plural)

Since exame is masculine singular (o exame), you get:

depois de o exame → depois do exame

So:

depois do exame ✅ correct for o exame
depois da prova ✅ if the noun is feminine (a prova)
Just depois de exame ❌ sounds wrong in standard Portuguese in this context.

Could I say após o exame or depois de o exame instead of depois do exame? Are they the same?

Meaning-wise, they are effectively the same: after the exam.

Forms:

depois do exame – most natural and common in everyday speech and writing.
após o exame – a bit more formal or literary, but perfectly correct.
depois de o exame – grammatically possible, but in practice people virtually always contract it to depois do exame. The contracted form is what you should use.

So for standard modern Portuguese (Portugal):

Prefer depois do exame in normal contexts.
Use após o exame if you want a slightly more formal or written style.

Can I leave out the article and say depois de exame?

In this context, no. The most natural option is with the article:

depois do exame ✅
depois de exame ❌ (unnatural for this meaning)

Portuguese normally uses the article with a specific event like o exame (“the exam” you are talking about).

There are some fixed expressions without an article (e.g. antes de almoço, depois de jantar in some varieties), but with exame here, the article is expected.

So, to sound natural: always depois do exame.

Is tristeza always feminine? Could I say um tristeza?

Tristeza is a feminine noun in Portuguese.

a tristeza – the sadness
uma tristeza – a sadness (in certain contexts)

So you must use feminine articles and adjectives:

a / uma tristeza ✅
aquela tristeza ✅ (“that sadness”)
muita tristeza ✅ (“a lot of sadness”)

You cannot say:

um tristeza ❌
o tristeza ❌

You can use uma tristeza in some idiomatic expressions, e.g.:

Foi uma tristeza. – “It was (such) a sad thing / It was really sad.”

But in your sentence, the neutral, general way is A tristeza....

Does this sentence refer to one specific exam, or can it also describe a general situation?

It can do both, depending on context.

Specific exam (most literal reading)
- There is a particular exam (for example, a medical exam or a school exam) that has already happened or that is understood from context.
- A tristeza às vezes volta depois do exame.
  → “Sadness sometimes comes back after the exam (that we’re talking about).”
General/habitual situation
- It can also describe what usually happens whenever there is an exam, as a general pattern:
  - “Sadness sometimes comes back after the exam” (whenever you have one).

Portuguese present tense (volta) is flexible: it can indicate both a specific present time or a habitual/general situation. The exact interpretation comes from context rather than from the tense alone.