Learn Hardcore Portuguese (Portugal): Ao fim da tarde, fizemos um passeio curto só para ver o rio. - In the late afternoon, we took a short walk just to see the river.

Ao fim da tarde literally is “at the end of the afternoon”, but in practice it usually means “in the late afternoon / towards the end of the afternoon”, and it can be used quite generally, not only for one specific afternoon.

ao fim da tarde – very common in European Portuguese, sounds natural and idiomatic for “late afternoon”.
no fim da tarde – also correct, a bit more literal: “at the end of the afternoon”. Used in both Portugal and Brazil.
à tarde – means “in the afternoon” in a general sense (not specifically late):
- Eu estudo à tarde. – I study in the afternoon.

So:

Ao fim da tarde ≈ during the late / tail end of the afternoon.
No fim da tarde ≈ at the end of the afternoon (more literally).
À tarde ≈ in the afternoon (broad, unspecific time).

Why is it da tarde and not de a tarde?

In Portuguese, certain prepositions combine (contract) with the definite articles o, a, os, as.

de + a = da
de + o = do
de + as = das
de + os = dos

So:

o fim da tarde = “the end of the afternoon”
literally: o fim de a tarde → o fim da tarde

You almost never say de a tarde; you use the contracted form da.

What exactly does fizemos um passeio mean? Why use fazer with passeio?

The verb fazer with passeio is a very common collocation:

fazer um passeio = to go for a walk / to take a walk / to go on a short trip/outing.

So fizemos um passeio is simply “we went for a walk”.

Other very common options with passeio:

dar um passeio – literally “to give a walk”, but it means exactly the same as fazer um passeio in this context.
passear – the verb “to walk (for leisure), to stroll, to go for a walk / outing”
- Fomos passear. – We went for a walk.

All are natural. Your sentence could also be:

Ao fim da tarde, demos um passeio curto só para ver o rio.
Ao fim da tarde, fomos passear só para ver o rio.

Why is the adjective placed after the noun in um passeio curto? Could I say um curto passeio?

In Portuguese, the neutral / most common position for adjectives is after the noun:

um passeio curto – a short walk
um carro novo – a new car
uma casa grande – a big house

You can say um curto passeio, but:

um passeio curto sounds more natural and everyday.
um curto passeio is possible but feels more formal, stylistic, or poetic.

So for normal speech, um passeio curto is what you should use.

What does só do in só para ver o rio? Is it like “just” or “only” in English?

Yes. Here só means “just / only” and expresses limitation of purpose:

só para ver o rio = just / only to see the river

It implies that the walk had no other big purpose: it was a small, simple walk just for that.

Some related points:

só vs apenas:
- só is more common in speech, a bit more informal.
- apenas is more formal or “written”, but still widely used.
- só para ver o rio ≈ apenas para ver o rio.
só can also mean “alone”:
- Ele está só. – He is alone.
  Context decides whether it’s “only/just” or “alone”.

The accent is important: só has a stressed open “ó” and is the normal, correct spelling of this word.

Why is it ver o rio and not just ver rio? Do we always need the article with rio?

Portuguese uses definite articles much more often than English, especially with concrete, countable nouns.

Here we say o rio (“the river”) because we are talking about a specific, identifiable river (the one both speaker and listener know about).

ver o rio – to see the river (that particular river)
ver rios – to see rivers (rivers in general, plural)
ver rio (without the article, singular) is usually odd or ungrammatical in this context.

In general, when you have a concrete noun like rio, carro, casa, you will usually use o / a / os / as if you mean a specific one:

Eu vi o carro. – I saw the car.
Eu comprei a casa. – I bought the house.

So ver o rio is the normal, natural form here.

Could it be para ver rio instead of para ver o rio to mean “to see a river / rivers (in general)”?

If you mean “to see a river / rivers (in general)”, you normally change the structure, for example:

só para ver o rio – just to see the river (a specific one).
só para ver um rio – just to see a river (any one river).
só para ver rios – just to see rivers (plural, in general).

The bare singular rio without an article, para ver rio, is generally wrong or at least very unnatural here.

Why is it para ver o rio and not por ver o rio or a ver o rio?

In this kind of purpose phrase (“in order to …”), Portuguese uses:

para + infinitive

So:

só para ver o rio – just (in order) to see the river.

Other prepositions:

por + infinitive is not used for purpose like this.
You might see por with infinitive in other, more idiomatic expressions, but not in this simple “in order to” sense.
a + infinitive can appear in some specific structures (e.g. with certain verbs: começar a fazer, continuar a trabalhar), but not to mean “in order to” here.

So the correct, natural form for purpose is para ver o rio.

What tense is fizemos, and why is it used here?

Fizemos is the pretérito perfeito do indicativo (simple past) of fazer, 1st person plural:

(nós) fizemos – “we did / we made / we took (a walk)”.

In European Portuguese, pretérito perfeito is used for:

completed actions in the past, seen as finished events.

This is why it’s used here: the walk is a single, completed action in the past.

Contrast with the imperfeito:

fazíamos um passeio ao fim da tarde – “we used to take a walk in the late afternoon” (habitual, repeated in the past).

In your sentence it’s about one particular occasion, so fizemos is the correct tense.

Could the word order around só change? For example, can I say só fizemos um passeio curto?

Yes, you can move só, but the meaning changes slightly depending on position:

fizemos um passeio curto só para ver o rio
Focus on the purpose: “We took a short walk just to see the river (for that purpose only).”
só fizemos um passeio curto para ver o rio
Focus on the kind/amount of activity:
“We only took a short walk to see the river (we didn’t do anything else).”

Both are correct.

In your original sentence, só modifies para ver o rio (the purpose).
In só fizemos, só modifies fizemos um passeio curto (the action itself).

Is ao fim da tarde more European Portuguese? What would Brazilians say?

Ao fim da tarde is especially common in European Portuguese.

In Brazilian Portuguese, you’re more likely to hear:

no fim da tarde
no final da tarde

Both mean essentially the same: “towards the end of the afternoon / late afternoon”.

In Portugal, all of these are understood, but:

ao fim da tarde sounds very natural and typical for European Portuguese.

Are there synonyms for um passeio curto that would sound natural in European Portuguese?

Yes, there are several natural alternatives with slightly different nuances:

uma caminhada curta – a short walk (more like walking for exercise or distance)
um pequeno passeio – a small/short walk (more “cute” / slightly more literary)
um passeio pequenino – a tiny little walk (very informal, expressive, maybe to a child)
um passeio rápido – a quick walk

Your original um passeio curto is clear, neutral, and very natural; it’s a good choice.

Why is tarde feminine and rio masculine? Is there a rule?

In Portuguese, grammatical gender is mostly arbitrary and must be learned with each noun:

a tarde – feminine
o rio – masculine

Often there is no logical reason; you just memorize the article with the noun.

However, there are some tendencies:

Nouns ending in -a are usually feminine:
- a casa, a rua, a mesa, a tarde.
Nouns ending in -o are usually masculine:
- o livro, o carro, o rio.

There are many exceptions, but this pattern does fit tarde (f.) and rio (m.).