Aunque ya es tarde, mi hermana sigue cocinando porque quiere terminar el puré.

Aunque means although / even though and introduces a contrast.

In this sentence, aunque ya es tarde presents something the speaker treats as a real, known fact, so Spanish uses the indicative: es.

• Aunque ya es tarde... = although it is already late

If the speaker wanted to sound less certain, more hypothetical, or more concessive, the subjunctive could appear:

• Aunque ya sea tarde... = even if it may already be late / although it may be late

So here, es is used because the lateness is presented as factual.

Spanish uses ser in the fixed expression es tarde = it’s late.

This is one of those common time-related expressions where English speakers often expect estar, but Spanish uses ser:

• Es tarde = It’s late
• Es pronto = It’s early

Está tarde is not natural Spanish for this meaning.

Here, ya means already.

• Aunque es tarde = Although it’s late
• Aunque ya es tarde = Although it’s already late

So ya emphasizes that the point of lateness has already been reached.

Be aware that ya can mean different things in other contexts, such as now, any more, or even a conversational okay / fine, but here it clearly means already.

This is the structure seguir + gerundio, which means to keep doing something or to continue doing something.

• seguir = to continue
• cocinando = cooking

So:

• mi hermana sigue cocinando = my sister is still cooking / keeps cooking / continues cooking

This is a very common Spanish pattern:

• Sigo estudiando = I’m still studying
• Siguen hablando = They keep talking

Both can describe an action happening now, but they are not exactly the same.

• está cocinando = she is cooking
• sigue cocinando = she is still cooking / she keeps cooking

Seguir + gerundio stresses continuation, especially when something might make you expect the action to stop. That fits well with aunque ya es tarde.

So the sentence suggests:

• it’s already late,
• but she has not stopped cooking.

Because porque means because.

This is a very common point of confusion:

• porque = because
• por qué = why
• el porqué = the reason
• por que = a less common combination used in certain structures

Here the sentence gives a reason:

• porque quiere terminar el puré = because she wants to finish the purée

So porque is the correct form.

After querer, Spanish normally uses an infinitive when the same person wants to do the action.

• quiere terminar = she wants to finish

The subject of both verbs is the same person: mi hermana.

Compare:

• Mi hermana quiere terminar el puré = My sister wants to finish the purée
• Mi hermana quiere que yo termine el puré = My sister wants me to finish the purée

In the second sentence, the subject changes, so Spanish uses que + subjunctive.

Spanish often drops subject pronouns because the verb form and context usually make the subject clear.

Here, mi hermana already tells us who is doing the action, so ella is unnecessary.

• Mi hermana sigue cocinando = natural
• Ella sigue cocinando = possible, but now ella is more emphatic
• Mi hermana, ella sigue cocinando = strongly emphatic or contrastive, not neutral

Spanish generally avoids subject pronouns unless they are needed for emphasis, contrast, or clarity.

Yes, puré is a masculine noun, so it takes el:

• el puré

Its gender is something you mostly learn with the word itself. The ending does not always make gender obvious.

In Spain, puré often refers to a purée, and in many everyday contexts it may specifically suggest mashed potatoes or a vegetable purée, depending on context.

The accent mark shows that the stress falls on the last syllable:

• pu-RÉ

Without the accent, Spanish spelling rules would normally make you stress it differently. So the written accent tells you the correct pronunciation.

It is a normal spelling accent, not optional.

Here, terminar el puré means to finish making / preparing the purée.

It does not mean something like to end the purée in a strange abstract sense. In Spanish, terminar is often used for finishing a task or completing something that is in progress.

So in context:

• she is still cooking
• because she wants to finish the purée

That is the natural interpretation.

The comma separates the introductory subordinate clause from the main clause:

• Aunque ya es tarde, mi hermana sigue cocinando...

This is very common and natural in Spanish when a clause like aunque ya es tarde comes first.

If the order changes, the punctuation may also change:

• Mi hermana sigue cocinando porque quiere terminar el puré, aunque ya es tarde.

So the comma helps the sentence read clearly, especially with the concessive clause at the beginning.