Aunque estoy cansado, quiero seguir hablando en español con mis amigos.

Aunque means although / even though. It introduces a contrast:

• Aunque estoy cansado = Although I’m tired
• quiero seguir hablando... = I want to keep speaking...

So the sentence is built around the idea: despite being tired, I still want to continue.

In Spanish, estar is used for states or conditions, while ser is used for more permanent characteristics.

• estoy cansado = I am tired (how I feel right now)
• soy cansado would mean something more like I am tiring / boring / exhausting as a person, which is not the intended meaning.

So for physical or temporary tiredness, Spanish uses estar.

Cansado is an adjective, and in Spanish adjectives usually agree with the person they describe.

• If the speaker is male: estoy cansado
• If the speaker is female: estoy cansada

If a group were speaking, it could also change:

• masculine/mixed group: estamos cansados
• all-female group: estamos cansadas

Spanish often omits subject pronouns because the verb ending already shows who the subject is.

• estoy = I am
• quiero = I want

So yo is not necessary. You could say Yo estoy cansado, but it usually sounds more emphatic, as if you are stressing I.

Quiero hablar means I want to speak.
Quiero seguir hablando means I want to keep speaking / continue speaking.

The word seguir adds the idea of continuation. It tells us the speaking has already started, and the speaker wants it to continue.

Seguir + gerund is a very common Spanish structure meaning to keep doing something or to continue doing something.

Examples:

• seguir hablando = to keep speaking
• seguir estudiando = to keep studying
• seguir trabajando = to keep working

In your sentence:

• quiero seguir hablando = I want to keep speaking

This is similar to English keep + -ing.

After seguir, Spanish normally uses a gerund to express continuing an action:

• seguir hablando
• seguir comiendo
• seguir leyendo

So seguir hablar is not correct here.
The correct pattern is seguir + gerund.

Both can exist, but they are used a little differently.

• hablar español = to speak Spanish (the language in general)
• hablar en español = to speak in Spanish (emphasising the language being used in that situation)

In this sentence, hablando en español con mis amigos highlights that the conversation is taking place in Spanish.

Yes, you could say:

• Aunque estoy cansado, quiero seguir hablando español con mis amigos.

This is natural too. The difference is small:

• hablar español focuses more on speaking the language
• hablar en español focuses more on using Spanish in that conversation

In many contexts, both are acceptable.

Con mis amigos means with my friends and tells us who the speaker wants to keep speaking with.

Placing it at the end is very natural in Spanish:

• quiero seguir hablando en español con mis amigos

Spanish word order is flexible, but this order sounds normal and clear. It keeps the main action together first, then adds the extra detail.

Yes, in many cases you may see aunque clauses written without a comma, especially in shorter sentences. But the comma is very common and helpful here because the first part is an introductory contrast:

• Aunque estoy cansado, quiero seguir hablando...

It makes the sentence easier to read. In practice, this punctuation is natural and correct.

Aunque can be followed by either the indicative or the subjunctive, depending on meaning.

Here, estoy cansado is a real, known fact: the speaker actually is tired. That is why the indicative is used.

• Aunque estoy cansado... = Although I am tired... (a real situation)

If the speaker were talking about something hypothetical or uncertain, the subjunctive could appear in other contexts.

Both are correct, but seguir hablando is usually more common and everyday.

• seguir hablando = very common in normal speech
• continuar hablando = also correct, sometimes a bit more formal or less conversational

So in this sentence, seguir hablando sounds very natural.

Yes. In Spanish, the masculine plural is used for:

• a group of all males
• a mixed group of males and females
• sometimes when gender is unspecified

So mis amigos can mean:

• my male friends
• my friends in a mixed group
• my friends when not specifying gender

If the group is all female, it would be mis amigas.

Only the adjective would need to change:

• Aunque estoy cansada, quiero seguir hablando en español con mis amigos.

If she is talking with female friends only, she could also say:

• Aunque estoy cansada, quiero seguir hablando en español con mis amigas.

So the key change is agreement in cansada and possibly amigas if appropriate.

The sentence has two main parts:

1. Aunque estoy cansado
   = a contrast clause
   = Although I’m tired

2. quiero seguir hablando en español con mis amigos
   = the main clause
   = I want to keep speaking in Spanish with my friends

So the overall pattern is:

Aunque + clause, main clause

This is a very common way to express contrast in Spanish.