Ontem à tarde, eu fui ao mercado e comprei pão.

Ontem à tarde is a time expression meaning yesterday afternoon. In Portuguese, just like in English, it is very common to put time expressions at the beginning of a sentence to set the scene first.

So:

• Ontem à tarde, eu fui ao mercado... = Yesterday afternoon, I went to the market...

You could also move it:

• Eu fui ao mercado ontem à tarde...

Both are correct. Starting with the time phrase just gives it a natural storytelling feel.

À is not the same as a.

Here, à tarde is a fixed time expression meaning in the afternoon. The à is a contraction of:

• a
  • a

This is called a crase in Portuguese.

Some common expressions like this are:

• de manhã = in the morning
• à tarde = in the afternoon
• à noite = at night / in the evening

So in this sentence, Ontem à tarde is the normal way to say yesterday afternoon.

You can absolutely omit eu here.

Portuguese often drops subject pronouns when the verb form already makes the subject clear. Since fui clearly means I went, native speakers often say:

• Ontem à tarde, fui ao mercado e comprei pão.

This is very natural in Brazilian Portuguese.

Including eu is also correct. It may sound a little more explicit or emphatic, but not wrong.

Fui is the first-person singular form of the verb ir (to go) in the pretérito perfeito.

That tense is used for a completed action in the past.

So:

• eu fui = I went

In this sentence, the speaker is talking about a finished event that happened yesterday, so fui is the right tense.

Compare:

• eu fui ao mercado = I went to the market
• eu ia ao mercado = I was going / I used to go to the market

Since this is one completed trip, fui fits best.

Because the verb ir normally uses the preposition a when talking about going to a place.

So:

• ir a
  • o mercado = ir ao mercado

The ao is a contraction:

• a + o = ao

That is why you get:

• fui ao mercado = I went to the market

This is a very important pattern in Portuguese:

• vou ao banco = I go / am going to the bank
• fomos à praia = we went to the beach
• ele foi aos Estados Unidos = he went to the United States

Ao means to the.

It is formed from:

• a = to
• o = the

So:

• ao mercado = to the market

This kind of contraction is extremely common in Portuguese:

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

So fui ao mercado literally breaks down as I went to the market.

Comprei is the pretérito perfeito of comprar (to buy) in the eu form.

So:

• eu comprei = I bought

Just like fui, it describes a completed action in the past.

The sentence tells two completed actions in sequence:

1. fui ao mercado = I went to the market
2. comprei pão = I bought bread

This is a very common use of the pretérito perfeito in Portuguese.

Because the subject is still the same: eu.

In Portuguese, once the subject is clear, it is often omitted, especially when two verbs share the same subject.

So:

• eu fui ao mercado e comprei pão

means:

• I went to the market and bought bread

You could say:

• eu fui ao mercado e eu comprei pão

but that sounds more repetitive unless you are emphasizing I.

Because Portuguese often uses a bare noun when speaking in a general sense, especially with food or things being bought, eaten, or consumed.

So:

• comprei pão = I bought bread

This sounds natural if you mean bread in general.

If you say:

• comprei um pão

that sounds more like I bought a loaf / one bread item, depending on context.

If you say:

• comprei o pão

that usually means I bought the bread, referring to specific bread already known in the conversation.

So all three are possible, but they mean slightly different things:

• comprei pão = bought bread
• comprei um pão = bought a bread / one loaf/item
• comprei o pão = bought the bread

Sometimes yes, but not always exactly.

In Brazilian Portuguese, mercado can mean:

• a market
• a grocery store
• sometimes even a supermarket in everyday speech

So fui ao mercado could mean:

• I went to the market
• I went to the grocery store

If you want to be more specific, you might also hear:

• supermercado = supermarket
• feira or feira livre = street market / open-air market

In casual Brazilian speech, mercado is very common for the place where you buy groceries.

Yes. Portuguese allows some flexibility in word order, especially with time expressions.

These are all possible:

• Ontem à tarde, eu fui ao mercado e comprei pão.
• Eu fui ao mercado ontem à tarde e comprei pão.
• Eu fui ao mercado e comprei pão ontem à tarde.

The first version is especially natural when you want to highlight when it happened.

The most neutral and common storytelling structure is often:

• time expression + subject + verb

So the original sentence sounds very natural.

In Brazilian Portuguese, fui is usually pronounced roughly like foo-ee, but as one smooth syllable-like glide rather than two strongly separate syllables.

A simple approximation for an English speaker is:

• fui ≈ fwee or foo-ee

The ui part glides together.

Also:

• f sounds like English f
• u is like oo in food
• i is like ee in see

So fui should sound short and smooth.

Because both actions are presented as completed events in a sequence.

The sentence tells a simple past narrative:

• first, I went
• then, I bought

Portuguese often uses the pretérito perfeito for this exact purpose.

So:

• fui = went
• comprei = bought

If the speaker wanted to describe an ongoing background action or habit, a different tense might be used. But for a completed sequence yesterday, this tense is the normal choice.

Not in this sentence, if you mean went to the market.

• ao mercado = to the market
• no mercado = in the market / at the market

So:

• fui ao mercado = I went to the market
• estava no mercado = I was at the market

This is a very important distinction:

• ir a = to go to
• estar em = to be in / at

So the original sentence needs ao mercado, not no mercado.