Lançamos o dado na mesa.

Portuguese often leaves out subject pronouns when the verb form already makes the subject clear.

Here, lançamos tells you the subject is we (nós), so Nós lançamos o dado na mesa is possible, but nós is usually omitted unless you want emphasis, contrast, or extra clarity.

It can be either one.

For nós verbs, the present and the preterite (simple past) sometimes have the same form:

• nós lançamos = we throw / we are throwing
• nós lançamos = we threw

So the sentence by itself is grammatically ambiguous. Context tells you which one it is.

For example:

• Sempre lançamos o dado na mesa. = habitual present
• Ontem lançamos o dado na mesa. = past

Lançar basically means to throw, to cast, or to launch.

With dado, it can work in a game context as cast/throw the die. In natural Brazilian Portuguese, people may also say:

• jogar o dado
• rolar o dado

So lançar o dado is understandable and fine, but depending on context, jogar or rolar may sound more everyday.

Because Portuguese usually uses an article where English may or may not use one.

Here:

• o = the
• dado = masculine singular noun

So o dado means the die.

Portuguese often sounds more natural with articles in places where English might leave them out.

You could also have:

• um dado = a die
• o dado = the die

In Portuguese:

• um dado = one die
• dois dados = two dice

So o dado is singular: it refers to one die.

The plural is os dados.

Because em + a contracts to na.

So:

• em a mesa → na mesa

This is a very common contraction in Portuguese.

Similar contractions:

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

Since mesa is feminine (a mesa), the correct form is na mesa.

Yes. In Portuguese, em can cover several meanings that English splits into different prepositions, such as in, on, and sometimes at, depending on context.

So with a surface like a table, na mesa often means:

• on the table

This is completely normal Portuguese. You do not always need a separate word equivalent to English on.

Because those expressions mean something slightly different.

• na mesa = on the table
• à mesa = at the table, usually in the sense of being seated there, especially for eating
• sobre a mesa = on top of the table, more literal or more emphatic

So for putting or throwing a die onto the table, na mesa is the most natural everyday choice.

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

So lançamos is pronounced roughly like:

• lan-SAH-moos

A few useful details:

• ç = s sound
• ã is nasal, so the first syllable is nasalized
• in many Brazilian accents, the final o sounds more like u

So the pronunciation is approximately lãn-SAH-mus.

Also notice this spelling pattern:

• before a/o/u, Portuguese may use ç to keep the s sound: lançar
• before e/i, a regular c already has that sound: lancei