A embalagem do bolo está aberta.

A is the feminine singular definite article, meaning the.

It is used because embalagem is a feminine singular noun:

• a embalagem = the package / the packaging

In Portuguese, nouns usually need an article much more often than in English.

Embalagem usually means packaging, package, wrapper, or container, depending on context.

In A embalagem do bolo está aberta, it refers to the thing enclosing the cake, such as:

• the package
• the wrapping
• the box
• the container

So the best English translation depends on the situation, but the grammar stays the same.

Do is a contraction of:

• de + o = do

So:

• do bolo = of the cake

This is extremely common in Portuguese:

• de + a = da
• de + o = do
• de + as = das
• de + os = dos

So a embalagem do bolo literally means the packaging of the cake, or more naturally in English, the cake’s packaging / the package of the cake.

Because bolo is a masculine noun in Portuguese, so it takes o:

• o bolo = the cake

Grammatical gender in Portuguese does not always match anything logical in English. It is simply a property of the noun that affects articles and adjectives.

Portuguese has two main verbs for to be:

• ser → for essential, permanent, defining characteristics
• estar → for states, conditions, location, and situations

Here, aberta describes a current condition of the packaging, not a permanent characteristic. So:

• A embalagem do bolo está aberta. = The cake package is open.

Using é aberta would usually suggest something more like a general characteristic, not the temporary state of being open right now.

Está is the third-person singular form of estar in the present tense.

Conjugation of estar in the present:

• eu estou
• você/ele/ela está
• nós estamos
• vocês/eles/elas estão

Since the subject is A embalagem (singular), we use está.

Because aberta must agree with embalagem, which is feminine singular.

Agreement here is:

• embalagem → feminine singular
• adjective/past participle → aberta

Compare:

• O pacote está aberto. = The package is open.
• A embalagem está aberta. = The packaging is open.

So the ending changes to match the noun.

In this sentence, it works like an adjective describing the state of the packaging.

It comes from the verb abrir (to open), whose past participle is:

• aberto (masculine)
• aberta (feminine)

After estar, these forms often describe a state:

• está aberto = is open
• está fechada = is closed

So learners can think of it as the participle being used adjectivally.

No. Do bolo must stay next to embalagem because it tells us which packaging we are talking about: the cake’s packaging.

Natural order:

• A embalagem do bolo está aberta.

If you say A embalagem está aberta do bolo, it sounds ungrammatical or very unnatural.

Literally, it is closer to:

• The packaging of the cake is open

But in natural English, you might say:

• The cake package is open
• The cake packaging is open
• The cake box is open
• The wrapper is open

Portuguese often uses de + noun structures where English might prefer a noun used like an adjective.

Yes. Embalagem is a broad word.

Depending on context, it can mean:

• wrapping
• package
• box
• container
• packaging

If you want to be more specific, Portuguese also has words like:

• caixa = box
• pacote = package/packet
• embrulho = wrapping/package
• recipiente = container

But embalagem is very common and flexible.

The original sentence is already natural. In everyday speech, Brazilians might also say:

• O pacote do bolo tá aberto.
• A embalagem do bolo tá aberta.

Here, tá is the informal spoken form of está.

So:

• está = standard/written/formal
• tá = very common in speech

A rough pronunciation guide is:

ah em-bah-LAH-zhen do BOH-lo es-TAH ah-BEHR-tah

A few notes:

• lh does not appear here, but lh in Portuguese is different from English l
• the g in embalagem sounds like the s in measure
• está has stress on the last syllable: tá
• aberta has stress on ber

This is only an approximation, but it can help you get started.