Eu prefiro aquele, porque este está caro demais.

Yes, Portuguese often drops subject pronouns because the verb ending already shows who the subject is. So Prefiro aquele is completely natural.

However, eu can still be included:

• for emphasis
• for clarity
• to create a stronger contrast with someone else’s opinion

So:

• Prefiro aquele. = I prefer that one.
• Eu prefiro aquele. = I prefer that one / As for me, I prefer that one.

In this sentence, eu is not required, but it sounds perfectly normal.

These are demonstratives, words like this and that.

In this sentence:

• este = this one
• aquele = that one over there

The basic contrast is about distance:

• este = near the speaker
• esse = near the listener or less close
• aquele = farther away from both speaker and listener

So Eu prefiro aquele, porque este está caro demais suggests something like:

• I prefer that one over there, because this one is too expensive.

The sentence is contrasting two items.

Not always. In everyday Brazilian Portuguese, many speakers use esse where traditional grammar would expect este.

So in conversation, you may often hear:

• Eu prefiro aquele, porque esse está caro demais.

This is very common in Brazil.

That said, este is still correct and is more likely to appear:

• in careful speech
• in writing
• when someone wants a clearer contrast between this and that

So the sentence is grammatically correct and natural, but in casual Brazilian speech, esse may be more common.

Because in Portuguese, just like in English, the noun can be omitted when it is already understood from context.

For example, if you are looking at two phones, shirts, or apartments, you can say:

• Prefiro aquele.
• Este está caro demais.

The hidden noun might be something like:

• aquele celular
• este carro
• aquele livro

English does the same thing:

• I prefer that one.
• This one is too expensive.

So aquele and este are standing in for that one and this one.

Both ser and estar can be used with adjectives, but the meaning can change.

• é caro often describes something as generally or inherently expensive
• está caro often refers to the current price or current situation

In this sentence, este está caro demais usually means:

• this one is too expensive right now
• this one costs too much

That is why estar sounds very natural here. It focuses on the price as a current condition.

Compare:

• Carne está cara. = Meat is expensive right now.
• Esse restaurante é caro. = That restaurant is an expensive restaurant in general.

Caro means expensive.

Demais here means too much or overly.

So:

• caro demais = too expensive

A very common pattern in Portuguese is:

• adjective + demais

Examples:

• difícil demais = too difficult
• longe demais = too far
• rápido demais = too fast

So este está caro demais means this one is too expensive.

That is the normal position for demais in this meaning.

Portuguese often puts intensity words after the adjective in expressions like:

• bonito demais = too beautiful / beautiful للغاية? Actually in Portuguese this often means very beautiful, depending on context
• caro demais = too expensive
• tarde demais = too late

So demais usually comes after the adjective or adverb it modifies.

This is different from English, where too comes before:

• too expensive
• too late

Because here it means because, giving the reason.

Portuguese has several similar-looking forms:

• porque = because
• por que = why / for what reason / by which
• porquê = the reason
• por quê = why, usually at the end of a question

In your sentence, the second clause explains the reason for the preference:

• Eu prefiro aquele, porque este está caro demais.

So porque is exactly the right form.

Many learners want to build prefer like English, but Portuguese works a bit differently.

The most standard structure is:

• prefiro X a Y

So you could say:

• Prefiro aquele a este.

That is better than prefiro aquele do que este in formal grammar.

In everyday speech, though, people often avoid the full comparison and simply say:

• Eu prefiro aquele.
• Eu gosto mais daquele.

In your sentence, the comparison is already clear from context, so Eu prefiro aquele sounds natural.

Because they agree with the noun they replace.

If the omitted noun is masculine singular, you use:

• este
• aquele

For example:

• este carro
• aquele livro

If the noun were feminine singular, you would use:

• esta
• aquela

Example:

• Prefiro aquela, porque esta está cara demais.
  • Here the hidden noun could be camisa, mesa, bolsa, etc.

Plural forms:

• estes / aqueles for masculine plural
• estas / aquelas for feminine plural

So the form changes to match the gender and number of the noun being referred to.

The accent in está shows the stressed syllable and distinguishes the verb form clearly in writing.

• está = is
• from the verb estar

Portuguese uses accent marks to indicate pronunciation and sometimes to distinguish words.

Here, está is the third-person singular form:

• ele/ela/você está

Since the subject is este (this one), the verb must be singular:

• este está

Yes. Portuguese allows some flexibility.

The original sentence:

• Eu prefiro aquele, porque este está caro demais.

You could also say:

• Porque este está caro demais, eu prefiro aquele.

That version puts more emphasis on the reason first.

However, the original order sounds very natural and straightforward:

1. statement of preference
2. explanation

So it is probably the most neutral version.

A very everyday Brazilian version might be:

• Eu prefiro aquele, porque esse está caro demais.

Or even:

• Prefiro aquele, porque esse tá caro demais.

Notes:

• esse is often more common than este in casual Brazilian speech
• tá is the spoken short form of está

So:

• Eu prefiro aquele, porque este está caro demais. = correct, clear, slightly more careful
• Prefiro aquele, porque esse tá caro demais. = very natural in casual spoken Brazilian Portuguese

Both are useful to know.