Learn Hardcore Portuguese (Portugal): Vou guardar este livro para sempre.

In contemporary European Portuguese, vou guardar is more common in everyday speech than guardarei, which can sound more formal, literary, or emphatic. Both are correct; the choice is mostly about style and level of formality, not meaning.

Why is the subject eu (I) not written? Could you say Eu vou guardar este livro para sempre?

Portuguese is a pro‑drop language, meaning the subject pronoun is often omitted because the verb ending (or here, the conjugation of ir) already shows who the subject is.

Vou guardar este livro para sempre. = I’m going to keep this book forever.
The vou form already implies eu, so saying eu is not necessary.

You can say:

Eu vou guardar este livro para sempre.

Adding eu usually adds emphasis or contrast, for example:

Eu vou guardar este livro para sempre, mas tu podes dá-lo a alguém.
I am going to keep this book forever, but you can give it to someone.

What exactly does guardar mean here? Why guardar and not ter or manter?

Guardar in this sentence means to keep / to hang on to / to store carefully. It suggests:

not throwing it away, not giving it away
keeping it safe, often with some care or intention

Rough comparisons:

guardar um livro – keep the book, not get rid of it, possibly put it in a safe place.
ter um livro – simply “have/own a book”; it doesn’t say anything about your intention to preserve it.
manter um livro – “maintain/keep it (in some state)”; used more for keeping something as it is (e.g. manter o livro em bom estado).

So vou guardar este livro para sempre focuses on the decision and intention to keep and preserve the book, not just owning it.

What’s the difference between este, esse, and aquele in European Portuguese, and why is it este livro here?

In European Portuguese, the basic idea is:

este / esta / estes / estas – near the speaker (“this / these”)
esse / essa / esses / essas – near the listener or just mentioned (“that / those”)
aquele / aquela / aqueles / aquelas – far from both (“that … over there”)

In practice, especially in speech:

este is often used like English “this”, for something the speaker has in their hand, right next to them, or very present in the situation.

So este livro naturally fits:

The speaker is probably holding the book, pointing to it, or it’s clearly the book they’re talking about.

You could say esse livro in some contexts, but este livro is the most straightforward if the book is “with” the speaker.

Can para sempre go in other positions in the sentence, like in English “I’m going to keep this book forever”?

Yes, para sempre (forever) is fairly flexible. All of these are possible:

Vou guardar este livro para sempre.
Vou guardar para sempre este livro.
Este livro vou guardar para sempre. (more emphatic, “This book I’m going to keep forever”)

The most neutral and common is the original:

Vou guardar este livro para sempre.

If you put para sempre earlier (e.g. Vou para sempre guardar este livro), it’s still understandable but sounds unusual, overly formal, or poetic. In normal conversation, prefer keeping para sempre at the end or just after the verb phrase.

Does para sempre mean literally “forever,” or can it just mean “for a very long time”?

Literally, para sempre = forever / for all time.

In practice, it can be:

Literal:
- Vou amar-te para sempre. – I’ll love you forever.
Hyperbolic / emotional, like in English, often just meaning “for a very long time” or “I never want to stop/lose this”:
- Vou guardar este livro para sempre. – I’m going to keep this book forever.
  (Realistically, maybe not literally infinite time, but the intention is “never get rid of it”.)

So functionally, it works very much like English “forever”.

Is vou guardar neutral, formal, or informal? Would it work in both spoken and written European Portuguese?

Vou guardar is neutral and very common:

Perfectly fine in informal conversation.
Also fine in informal writing (messages, emails, etc.).
Acceptable in most neutral written contexts (e.g. a personal note, straightforward narrative).

In very formal or legal texts, you might see the simple future guardarei instead of vou guardar, but even then vou guardar is not “wrong”; it’s just more conversational.

How would you say “I’m not going to keep this book forever” and “Are you going to keep this book forever?” using this structure?

For the negative:

Não vou guardar este livro para sempre.
I’m not going to keep this book forever.

Note that não (not) simply goes before the conjugated verb (here, vou).

For the question:

Vais guardar este livro para sempre? – to tu (informal “you”)
Vai guardar este livro para sempre? – to você (more formal / polite “you”)

In European Portuguese, you usually don’t change the word order in yes/no questions; you mostly rely on intonation and context, plus a question mark in writing.

If I want to replace este livro with a pronoun, where does it go? For example, “I’m going to keep it forever.”

With object pronouns, European Portuguese often uses enclisis (pronoun attached to the verb). With the ir + infinitive future, an object pronoun usually attaches to the infinitive:

Vou guardá‑lo para sempre. – I’m going to keep it (masculine) forever.
- o (him/it) → becomes ‑lo attached to guardar.

Some options you might see:

Vou guardá‑lo para sempre. (very natural)
Hei de guardá‑lo para sempre. (a different future structure, more formal/literary)

In everyday European Portuguese, Vou guardá‑lo para sempre is the natural way to say “I’m going to keep it forever,” assuming o livro is already known.

Is guardar ever reflexive, like guardar-se? Does that change the meaning?

Yes, guardar can be used reflexively as guardar-se, and then it changes meaning:

guardar-se (de / contra) – to protect oneself, to be careful/beware of
- Guarda-te do frio. – Protect yourself from the cold.
- Ela guarda-se muito bem. – She takes good care of herself / protects herself (context-dependent).

In your sentence, Vou guardar este livro para sempre, guardar is not reflexive and simply takes a direct object (este livro).

So Vou guardar-me would not mean “I’m going to keep myself (as in, keep me forever)” in the same sense; it would sound more like “I’m going to protect myself” or “I’m going to hold back / restrain myself,” depending on context.