Learn Hardcore Portuguese (Portugal): Na infância, eu passava horas a ler livros de mistério em vez de brincar na rua. - In my childhood, I spent hours reading mystery books instead of playing in the street.

Na infância literally means “in (the) childhood” and is a very natural, idiomatic way in European Portuguese to mean “in my childhood / when I was a child.”

Na infância = em + a infância
- em (in) + a (the, feminine singular) → na
It usually refers to the speaker’s own childhood without needing to say minha.

Alternatives:

Quando era criança – very common and natural; literally “when I was a child.”
Durante a minha infância – also correct, a bit more explicit and slightly more formal or careful.

All three are correct. Na infância is just a compact, idiomatic option.

Why is it Na infância (with na) and not just Em infância?

In Portuguese, abstract time periods almost always take a definite article:

na infância (in childhood)
na adolescência (in adolescence)
no verão (in the summer)
na segunda-feira (on Monday)

So the structure is:

em (in) + a infância (the childhood) → na infância

Saying em infância (without the article) is ungrammatical in this context. You need the article a → na infância.

Why is the verb passava used, and not passei? What’s the difference?

Passava is the imperfect past tense, while passei is the preterite (simple past).

eu passava horas a ler
= I used to spend hours reading / I would spend hours reading (habitual, repeated action in the past)
eu passei horas a ler
= I spent hours reading (on one specific occasion or limited time frame)

In this sentence, we’re describing a general habit in childhood, not one particular day, so the imperfect (passava) is the natural choice.

What does the structure passava horas a ler mean exactly? Why a ler and not something like ler alone or lendo, like in Brazilian Portuguese?

In European Portuguese, a very common pattern is:

passar [tempo] a + infinitive

Examples:

passar horas a ler – to spend hours reading
passar o dia a estudar – to spend the day studying
passar a noite a trabalhar – to spend the night working

So:

eu passava horas a ler
= I used to spend hours reading

You could say eu passava horas a ler (European) vs. eu passava horas lendo (more Brazilian style).
In European Portuguese, lendo is much less common; a ler is the normal structure here.

You cannot just say eu passava horas ler – you need the preposition a before the infinitive.

Is a ler here a kind of “progressive” tense, like English “was reading”?

No. In this sentence a ler does not form a progressive tense; it belongs to the “passar tempo a + infinitive” construction.

eu passava horas a ler
= I used to spend hours reading
(focus on the habitual duration, not on “I was in the middle of reading.”)

A true progressive idea (ongoing at a specific moment) in European Portuguese is usually:

estava a ler – was reading

So be careful:

eu passava horas a ler – I used to spend hours reading (habit in the past)
eu estava a ler – I was reading (at that specific time)

Why is it livros de mistério and not livros de mistérios?

In Portuguese (as in English), when a noun is used to classify another noun (like a genre or type), it often appears in the singular:

livros de mistério – mystery books (genre)
filmes de terror – horror films
histórias de amor – love stories
músicas de rock – rock songs

So de mistério = “of mystery” as a genre label.
Livros de mistérios would sound like “books of (many) mysteries” – grammatically possible, but it doesn’t sound like a literary genre label; it sounds more literal and is not what you normally say for “mystery novels.”

What is the nuance of em vez de? Could I say ao invés de instead?

Em vez de means “instead of” and is the standard, neutral expression:

em vez de brincar na rua – instead of playing in the street

Ao invés de is often used colloquially as a synonym, but traditionally it means “in the opposite way to”, not simply “instead of.” In everyday usage, many people treat them as the same, but:

In careful or formal writing, em vez de is preferred for “instead of.”
Ao invés de may sound a bit more informal or regional and can be considered less precise in standard European Portuguese.

So in this sentence, em vez de is the best, most standard choice.

Why is it brincar na rua and not jogar na rua? What’s the difference between brincar and jogar?

In European Portuguese:

brincar = to play in a childlike, general way
(run around, play pretend, play with toys, etc.)
jogar = to play games with rules, usually sports or board/card games

Examples:

brincar na rua – to play in the street (children playing generally)
brincar com bonecas – play with dolls
jogar futebol – play football
jogar cartas – play cards

So brincar na rua perfectly matches the idea of “playing outside as a child,” which is why brincar is used here.

Why is it na rua and not à rua or just rua?

You need the preposition + article:

em (in/on/at) + a rua (the street) → na rua

So:

brincar na rua = play in the street / outside

Using à rua would be wrong here. A as a preposition means “to”, and à rua (a + a rua) would suggest movement towards the street, not location on it.

You also can’t drop the article here; brincar em rua sounds wrong. Portuguese usually keeps the article with rua, casa, escola, etc., when they refer to a specific or generic place like this.

Could I leave out eu and just say Na infância, passava horas a ler…?

Yes. In Portuguese, subject pronouns are often omitted because verb endings show the subject.

Na infância, passava horas a ler livros de mistério…
is perfectly correct and would normally still be understood as “I”, from context.

Including eu:

adds emphasis (I, as opposed to others)
is also normal and not wrong

So both:

Na infância, eu passava horas a ler…
Na infância, passava horas a ler…

are correct. Including eu just makes the subject explicit.

Can I change the word order, like Eu, na infância, passava horas a ler…? Is that natural?

Yes, Portuguese allows some flexibility in word order, especially with time expressions. All of these are grammatically correct, with slight stylistic differences:

Na infância, eu passava horas a ler livros de mistério…
Eu, na infância, passava horas a ler livros de mistério…
Eu passava, na infância, horas a ler livros de mistério… (a bit heavier and more written-style)

The original version (Na infância, eu passava…) is very natural and neutral. Moving na infância after eu gives a slightly more spoken/storytelling feel, like you’re adding a side comment: “I, in my childhood, used to spend…”

If I wanted to say this about someone else, how would the verb change? For example, he used to spend hours reading.

You only need to change the subject and the verb ending:

Na infância, ele passava horas a ler livros de mistério em vez de brincar na rua.
– In childhood, he used to spend hours reading mystery books instead of playing in the street.

For she:

Na infância, ela passava horas a ler livros de mistério em vez de brincar na rua.

The imperfect tense form passava is the same for eu / ele / ela / você in European Portuguese. The pronoun (eu/ele/ela) tells you who it is.

Is there any agreement I should be careful about in livros de mistério and livros de mistério em vez de brincar na rua?

The key agreement points are:

livros – plural, masculine
de mistério – the noun mistério is singular, masculine, acting as a genre label, so it stays singular even though livros is plural.
na rua – rua is feminine singular, so:
- a rua → with em becomes na rua

Nothing else changes:

horas → plural feminine (hours)
passava → same form for eu, no extra agreement with horas

So the forms in the sentence are already correctly matched.