Vou ao centro comercial depois do almoço para comprar uma camisa nova.

Because Portuguese often leaves out subject pronouns when the verb ending already makes the subject clear. Vou is the 1st person singular form of ir (to go), so it already means I go / I’m going.

You can add eu if you want emphasis or contrast:

• Eu vou ao centro comercial, mas ele fica em casa.
  I’m going to the shopping centre, but he’s staying home.

Vou is the present indicative of ir (to go). In Portuguese, the present tense is often used for a planned or expected future action, especially when there is a time expression like depois do almoço.

So:

• Vou ao centro comercial depois do almoço.

can mean:

• I’m going to the shopping centre after lunch
• or I’ll go to the shopping centre after lunch

Here, vou is the main verb to go. It is not the future construction vou comprar (I’m going to buy)—in this sentence, comprar comes after para and expresses purpose.

Because ao is the required contraction of:

• a
  • o = ao

The verb ir often takes the preposition a when talking about going to a place, and centro comercial is a masculine singular noun phrase, so it uses the article o.

So:

• vou a o centro comercial → vou ao centro comercial

Other common contractions are:

• a + a = à
• a + os = aos
• a + as = às

Yes, you could. Both ir a and ir para can mean to go to.

Very roughly:

• ir a often sounds like going to a place as a destination
• ir para can sound a bit more like heading toward or going there for some purpose/stay

In this sentence, vou ao centro comercial is very natural and idiomatic.
Vou para o centro comercial is also possible, but ao is the more standard choice here.

Because Portuguese distinguishes between:

• movement toward a place → usually a / para
• location in a place → usually em

So:

• Vou ao centro comercial. = I’m going to the shopping centre.
• Estou no centro comercial. = I’m at/in the shopping centre.

Here the sentence is about going somewhere, so ao is correct.

In Portugal, centro comercial means shopping centre or mall.

Literally, it means commercial centre, but the normal English translation is shopping centre. In European Portuguese, this is a very common everyday term.

Do is a contraction of:

• de
  • o = do

The expression depois de means after, and here it is followed by o almoço (lunch), so:

• depois de o almoço → depois do almoço

So literally it is something like after the lunch, but in natural English we usually just say after lunch.

Portuguese uses the definite article much more often than English, including with many everyday nouns and meal names.

So Portuguese naturally says:

• depois do almoço = after lunch
• antes do jantar = before dinner

Even though English often has no article, Portuguese often does.

Para + infinitive expresses purpose. It means to, in order to, or for the purpose of doing something.

So:

• para comprar uma camisa nova

means:

• to buy a new shirt
• in order to buy a new shirt

It tells us why the speaker is going to the shopping centre.

Because camisa is a feminine singular noun.

In Portuguese, articles and adjectives usually agree with the noun in gender and number:

• uma camisa nova = feminine singular
• um casaco novo = masculine singular
• umas camisas novas = feminine plural

So both uma and nova match camisa.

Because in Portuguese, adjectives often come after the noun.

So the most neutral, ordinary way to say a new shirt is:

• uma camisa nova

Putting the adjective before the noun is sometimes possible, but it can sound more literary, emphatic, or slightly different in nuance. For basic everyday speech, camisa nova is the normal order.

Not always. In European Portuguese, camisa usually means a shirt, especially the kind with buttons or a collar.

Useful comparison:

• camisa = shirt
• t-shirt = T-shirt
• camisola = sweater / jumper / jersey, depending on context

So uma camisa nova will often suggest a proper shirt, not just any top.

Yes. Portuguese word order is quite flexible here.

You can say:

• Vou ao centro comercial depois do almoço para comprar uma camisa nova.
• Depois do almoço, vou ao centro comercial para comprar uma camisa nova.

Both are correct. Starting with Depois do almoço simply puts a bit more emphasis on when the action happens.