Em vez de pregar a prateleira, prefiro aparafusá-la e depois pintar a parede.

Em vez de is a fixed expression meaning instead of.

When it is followed by a verb, Portuguese uses the infinitive:

• em vez de pregar
• em vez de pintar
• em vez de esperar

So in this sentence, em vez de pregar a prateleira means instead of nailing the shelf.

A useful pattern is:

• em vez de + infinitive = instead of doing something

Examples:

• Em vez de sair, fiquei em casa. = Instead of going out, I stayed at home.
• Em vez de comprar, alugou. = Instead of buying, he/she rented.

Yes. Pregar can mean different things depending on context.

Common meanings include:

• to nail
• to preach
• in some expressions, even to play a trick

Here, because the object is a prateleira and the sentence contrasts it with aparafusar, the meaning is clearly to nail.

So:

• pregar a prateleira = to nail the shelf
• pregar um sermão = to preach a sermon

This is a very normal kind of verb ambiguity in Portuguese.

They describe different ways of fastening something:

• pregar = to attach with nails
• aparafusar = to attach with screws

So the speaker is saying they would rather use screws than nails.

You may also come across:

• parafusar = to screw
• aparafusar = to screw on / fasten with screws

In everyday use, aparafusar is very common for fastening something with screws.

Because preferir does not normally take de before an infinitive.

In Portuguese, preferir works more directly, like to prefer in English:

• Prefiro ficar em casa. = I prefer to stay at home.
• Prefiro esperar. = I prefer to wait.

So:

• prefiro aparafusá-la = I prefer to screw it on / fasten it with screws

By contrast, some Portuguese verbs do require a preposition before an infinitive, but preferir usually does not.

This is because Portuguese often attaches unstressed object pronouns to the end of the verb, especially in European Portuguese.

Here, la stands for a prateleira because prateleira is feminine singular:

• a prateleira → a / la as a direct object pronoun

So:

• aparafusar a prateleira = to screw the shelf on
• aparafusá-la = to screw it on

This attached pronoun is called enclisis.

In European Portuguese, this is very common, especially after infinitives:

• fazê-lo = to do it
• comprá-la = to buy it
• pintá-la = to paint it

When certain object pronouns are attached to an infinitive ending in -r, the final -r drops.

So:

• aparafusar + a does not become aparafusar-a

Instead, it becomes:

• aparafusá-la

What happens is:

1. the final -r is removed
2. the pronoun becomes -la
3. an accent is added to show the correct stress: -á-

The same happens with many other verbs:

• comprar + a → comprá-la
• fazer + o → fazê-lo
• pôr + o → pô-lo

This is a very important spelling pattern in Portuguese.

Because after verbs ending in -r, -s, or -z, the direct object pronouns o, a, os, as usually change form:

• o → lo
• a → la
• os → los
• as → las

So with aparafusar:

• expected object = a for a prateleira
• after final -r, it becomes -la
• result: aparafusá-la

Examples:

• ver + o → vê-lo
• fazer + as → fazê-las
• comprar + os → comprá-los

This avoids repeating the noun unnecessarily.

Portuguese often introduces the full noun first and then replaces it with a pronoun when referring to the same thing again.

So:

• pregar a prateleira
• aparafusá-la

This is very natural and sounds smoother than repeating a prateleira again.

Compare:

• Prefiro aparafusar a prateleira
• Prefiro aparafusá-la

Both are possible, but the second is more elegant and less repetitive.

Because depois can be used in two slightly different ways.

1. depois on its own = then / afterwards
2. depois de = after

In this sentence, depois means then or afterwards:

• ... e depois pintar a parede = ... and then paint the wall

If you said depois de pintar a parede, that would mean:

• after painting the wall

So the structure would be different.

Compare:

• Vou aparafusá-la e depois pintar a parede. = I’m going to screw it on and then paint the wall.
• Depois de pintar a parede, vou aparafusá-la. = After painting the wall, I’m going to screw it on.

Because a parede is being mentioned directly as a new object in that part of the sentence.

The pronoun -la earlier refers to a prateleira, not to a parede.

So the sentence has two different direct objects:

• a prateleira
• a parede

Portuguese often keeps the noun when it introduces or emphasizes a different object. Using pintá-la here would refer back to a feminine noun, but since there are now two feminine nouns in the sentence, it could be less clear.

So pintar a parede is clearer.

Because depois here is an adverb, not a noun.

It simply means then, afterwards, or later:

• e depois pintar a parede

Adverbs do not take articles in this use.

You may see:

• depois = afterwards
• logo depois = right after
• depois de = after

Yes, absolutely.

Both are correct:

• prefiro aparafusar a prateleira
• prefiro aparafusá-la

The version with -la is just less repetitive because a prateleira has already been mentioned.

European Portuguese often uses these attached pronouns very naturally, so aparafusá-la is a very typical and good example to learn from.

Yes, the use of enclitic pronouns like aparafusá-la is especially characteristic of standard European Portuguese style.

In Brazilian Portuguese, speakers very often prefer different structures in everyday language, for example:

• prefiro parafusar ela is heard in colloquial Brazilian speech, though it is not the most formal standard form
• more formal Brazilian Portuguese may also use aparafusá-la

So the sentence is perfectly correct Portuguese in general, but its style feels very natural for Portugal because of the attached pronoun.

In European Portuguese, unstressed vowels are often reduced, so the word may sound more compact than an English speaker expects.

Roughly:

• aparafusá-la

Key points:

• the stress is on -sá-
• the final -la is attached closely to the verb
• unstressed vowels before the stressed syllable may sound weaker

A learner should mainly notice:

1. the stress falls on sá
2. the pronoun is not pronounced separately as a full independent word
3. the whole form is said as one unit

Yes, when you compare two explicit alternatives.

Examples:

• Prefiro chá a café. = I prefer tea to coffee.
• Prefiro aparafusar a prateleira a pregá-la. = I prefer screwing the shelf on to nailing it.
• Prefiro isto do que aquilo. = I prefer this rather than that.

In your sentence, the comparison is already introduced by Em vez de..., so there is no need to add another comparison structure after prefiro.

That is why:

• Em vez de pregar a prateleira, prefiro aparafusá-la... sounds natural and complete.

Its main meaning is shelf, and that is the normal meaning here.

Depending on context, it can refer to:

• a shelf on a wall
• a shelf in a cupboard
• shelving in a shop or storage space

It is a feminine noun:

• a prateleira
• as prateleiras

That is why the pronoun later is feminine singular:

• aparafusá-la

It can help to break it into three parts:

1. Em vez de pregar a prateleira
   = instead of nailing the shelf

2. prefiro aparafusá-la
   = I prefer to screw it on / fasten it with screws

3. e depois pintar a parede
   = and then paint the wall

So the overall structure is:

• Instead of X, I prefer to do Y and then do Z.

This kind of infinitive-based structure is very common in Portuguese and is worth getting used to.