O peão avançou no tabuleiro.

O is the definite article, meaning the. Portuguese uses articles more often than English does, so o peão is the normal way to say the pawn.

You could sometimes say just peão, but that would sound less specific or would depend on context. In this sentence, o peão clearly refers to a particular pawn.

Here, peão means pawn, the chess piece.

Be careful, though: peão can also mean laborer, farm worker, or construction worker in other contexts. The word tabuleiro makes it clear that this sentence is about a board game, most likely chess.

-ão is a very common ending in Portuguese nouns. In peão, it is just part of the word.

For English speakers, the important thing is pronunciation: ão is a nasal sound, not a simple ow or an. It does not sound exactly like anything in English. You pronounce it with a nasalized vowel, roughly like owng without fully pronouncing the g.

Avançou is in the pretérito perfeito (simple past / preterite).

It is the third person singular form of avançar:

• eu avancei
• você/ele/ela avançou

So o peão avançou means that the action was completed: the pawn advanced.

Avançou describes a completed action: the pawn advanced.

Avançava would be the imperfect tense, usually used for:

• repeated actions in the past
• ongoing background actions
• descriptions

So:

• O peão avançou = the pawn advanced / moved forward
• O peão avançava = the pawn was advancing / used to advance

In this sentence, the completed action is the natural choice.

The infinitive is avançar, which means to advance or to move forward.

Other forms include:

• avanço = I advance
• avança = he/she/it advances
• avançaram = they advanced

So avançou is just one conjugated form of avançar.

The ç is called cedilha. It makes the c sound like s before a, o, or u.

So:

• avançou is pronounced with an s sound: avan-sou
• without the cedilla, c before a would sound like k

That is why Portuguese writes avançou, not avancou.

Because no is the contraction of em + o.

So:

• em + o = no
• em + a = na
• em + os = nos
• em + as = nas

Therefore, no tabuleiro literally comes from em o tabuleiro, but Portuguese normally contracts these forms.

Tabuleiro means board in the sense of a game board, like a chessboard or checkers board.

It can also mean tray in other contexts, so the exact meaning depends on the situation. Because of peão, here it clearly means a board used for a game.

In English, the natural translation is on the board.

Portuguese uses em much more broadly than English uses in. So even though em often means in, in many cases English will use on, at, or something else.

Here:

• no tabuleiro = on the board

Yes, but it changes the nuance.

• avançou specifically means advanced / moved forward
• se moveu means moved, in a more general sense

If you want to emphasize forward movement, especially with a pawn, avançou is a better choice.

This is the standard Portuguese word order: subject + verb + complement.

• O peão = subject
• avançou = verb
• no tabuleiro = location/complement

This is the most neutral and natural order for a simple statement.

A helpful approximation is:

o pe-ÃO avan-SOU no tabu-LEI-ro

A few pronunciation notes:

• o at the beginning is usually short, often close to oo or oh, depending on accent
• peão has stress on the last syllable
• avançou also has stress on the last syllable
• tabuleiro has stress on lei

In Brazilian Portuguese, it should sound smooth and connected: O peão avançou no tabuleiro.

Most likely, yes, because peão and tabuleiro strongly suggest a board game, especially chess.

However, without more context, it is not absolutely limited to chess. In practice, though, a learner should understand it as a chess-related sentence unless the surrounding context says otherwise.