Eu vou ler a carta.

In Brazilian Portuguese, ir + infinitive is a very common way to talk about the future, just like going to + verb in English.

So:

• vou ler = I am going to read / I will read

There is also a simple future form:

• lerei = I will read

But in everyday spoken Brazilian Portuguese, vou ler is much more common and natural.

Vou is the first-person singular form of the verb ir, which means to go.

Here is the relevant part of the conjugation:

• eu vou = I go / I am going
• você vai = you go
• ele/ela vai = he/she goes

In eu vou ler, vou is not really about physically going somewhere. It is helping form the future: I am going to read.

Yes. Portuguese often allows the subject pronoun to be omitted because the verb form already shows who the subject is.

So both of these are correct:

• Eu vou ler a carta.
• Vou ler a carta.

Both mean I am going to read the letter.

Including eu can add emphasis, clarity, or contrast. For example:

• Eu vou ler a carta, não você.
  I am going to read the letter, not you.

After ir when it is used to express the future, the main verb stays in the infinitive.

So:

• vou ler = I am going to read
• vai ler = you/he/she is going to read
• vamos ler = we are going to read

Only ir changes. The main verb ler stays the same.

Ler means to read. It is an -er verb.

Its infinitive is ler, and some present-tense forms are:

• eu leio = I read
• você lê = you read
• nós lemos = we read

But in your sentence, it appears in the infinitive because it follows vou:

• vou ler

The a here is the feminine singular definite article, meaning the.

• a carta = the letter

This is because carta is a feminine noun in Portuguese.

Compare:

• o livro = the book
• a carta = the letter

So this a is not a separate pronoun or preposition here. It is just the article the.

In Portuguese, nouns have grammatical gender. Carta is feminine, so it takes feminine words with it:

• a carta = the letter
• uma carta = a letter
• esta carta = this letter

Many nouns ending in -a are feminine, though not all. In this case, carta is feminine, and that is why the sentence uses a, not o.

Yes. In Brazilian Portuguese, a in a carta is usually pronounced like an open ah sound, not like the English ay in a book.

So:

• a carta sounds roughly like ah KAR-tah

The exact pronunciation can vary by region, but it is generally a short vowel sound, not the English article sound.

A rough pronunciation guide is:

• Eu vou ler a carta.
• roughly: eh-ooh voh lehr ah KAR-tah

A few notes:

• eu often sounds like eh-ooh in Brazilian Portuguese
• vou rhymes roughly with go but with a Portuguese vowel quality
• ler has a sound like lehr
• carta has stress on the first syllable: CAR-ta

The natural rhythm is smooth: Eu vou ler a carta.

Yes. In many contexts, vou ler can be translated either way in English:

• I am going to read the letter
• I will read the letter

Portuguese does not always separate those two ideas as strictly as English sometimes does. The context tells you whether it feels more like a plan, an intention, or a simple future action.

The normal word order is:

• Eu = subject
• vou ler = verb phrase
• a carta = object

So:

• Eu vou ler a carta.

This is the most neutral and natural order.

Portuguese can sometimes change word order for emphasis, but beginners should stick with the standard pattern: subject + verb + object.

Yes, that is grammatically correct.

• Eu vou ler a carta.
• Eu lerei a carta.

Both mean I will read the letter.

The difference is mainly style and usage:

• vou ler sounds more common and natural in everyday Brazilian Portuguese
• lerei sounds more formal, literary, or less conversational

So if you are learning everyday Brazilian Portuguese, vou ler is usually the better choice.

Yes, but the meaning changes slightly.

• a carta = the letter
  This refers to a specific letter.
• uma carta = a letter
  This refers to a letter, not necessarily one already identified.

So:

• Eu vou ler a carta. = I am going to read the letter.
• Eu vou ler uma carta. = I am going to read a letter.

The grammar stays the same; only the article changes.