El dau és sobre el tauler.

El is the masculine singular definite article, meaning the.

Both dau and tauler are masculine singular nouns, so they take el:

• el dau = the die
• el tauler = the board

If the noun were feminine, you would normally use la instead.

Yes. Dau is the singular form, meaning die.

The plural is daus, meaning dice:

• el dau = the die
• els daus = the dice

This is useful because English speakers often think of dice first, but Catalan clearly distinguishes singular and plural here.

In Catalan, ser and estar do not match English to be in exactly the same way.

Here, és is the form of ser for he/she/it is. In a simple neutral statement of location like this, ser can be used naturally.

You may also hear està in everyday speech:

• El dau és sobre el tauler.
• El dau està sobre el tauler.

Both can occur, depending on dialect and nuance. The version with és is perfectly correct, and it fits the sentence you were given.

Sobre is a preposition. In different contexts, it can mean:

• on
• over
• above
• about / regarding

In this sentence, it means on or on top of:

• sobre el tauler = on the board

So here it is a physical-location preposition.

No. Another very common option is damunt de:

• El dau és damunt del tauler.

That also means The die is on the board.

Very roughly:

• sobre is a general, standard way to say on/over
• damunt de often feels very physical: on top of

In many situations, both are possible.

Because sobre does not contract with the article.

Catalan has some common contractions, for example:

• a + el = al
• de + el = del
• per + el = pel

But with sobre, you keep the two words separate:

• sobre el tauler — correct

So sobre el is exactly what you should expect.

The accent is important in writing.

És with an accent means is.

Without the accent, es is a different word, often a pronoun used in reflexive or impersonal constructions.

So:

• és = is
• es = a grammatical pronoun, not the verb is

The accent helps distinguish them clearly.

A simple English-friendly guide:

• dau sounds roughly like dow in downtown
• tauler is roughly tow-LER or tau-LER, with the stress on the last part

A few helpful points:

• the au in dau and tauler is like the ow sound in now
• és is pronounced like ess
• sobre is roughly SOH-breh in a careful pronunciation

Exact pronunciation varies by dialect, but that approximation will get you close.

The basic word order here is very normal:

• El dau = subject
• és = verb
• sobre el tauler = location

So El dau és sobre el tauler is a straightforward, neutral sentence.

Catalan can change word order for emphasis, but this version is the easiest and most natural for a simple statement.

You would change the article, the noun, and the verb:

• Els daus són sobre el tauler. = The dice are on the board.

Changes:

• el → els
• dau → daus
• és → són

If the board were also plural:

• Els daus són sobre els taulers.

Not only. Tauler can mean different kinds of boards or panels depending on context.

Common uses include:

• a game board
• a chessboard
• a board or panel

In this sentence, because of dau (die), the game-related meaning is the most natural one.