Learn Hardcore Spanish (Spain): Hoy estoy cansado; aun así, quiero seguir estudiando español. - Today I am tired; even so, I want to keep studying Spanish.

Estoy cansado = I am tired (right now / today; it’s a temporary condition).
Soy cansado would suggest that being tired is an essential or habitual characteristic of you (almost like “I’m a tiring person” or “I’m someone who’s always tired”), and it sounds strange in most contexts.

So with feelings and physical states that change, like cansado, contento, triste, enfermo, you normally use estar.

Why is it cansado and not cansada? What if a woman is speaking?

Adjectives must agree in gender and number with the subject:

Male speaker: Estoy cansado.
Female speaker: Estoy cansada.
Group of men / mixed group: Estamos cansados.
Group of only women: Estamos cansadas.

In your sentence, cansado assumes the speaker is male (or that we’re using the masculine as a default). A female speaker would say:

Hoy estoy cansada; aun así, quiero seguir estudiando español.

Why is there a semicolon (;) instead of a comma or a word like pero?

The semicolon links two complete sentences that are closely related:

Hoy estoy cansado; aun así, quiero seguir estudiando español.

You could also write:

Hoy estoy cansado, pero quiero seguir estudiando español.
Hoy estoy cansado. Aun así, quiero seguir estudiando español.

All are correct. The semicolon style is a bit more formal or literary and puts a slight pause between the two ideas, stronger than a comma but weaker than a full stop.

What is the difference between aun así, aunque, and sin embargo?

All three introduce a contrast, but they behave differently:

aun así ≈ even so, still, nevertheless
- Usually comes after a pause (comma, semicolon, or full stop).
- It refers back to the previous idea as a whole.
- Example: Estoy cansado; aun así, estudio.
aunque ≈ although, even though
- It introduces a subordinate clause.
- It usually goes directly before a clause with a verb.
- Example: Aunque estoy cansado, estudio.
sin embargo ≈ however, nevertheless
- Very similar in use to aun así, slightly more formal.
- Example: Estoy cansado; sin embargo, estudio.

In your sentence, you could say:

Hoy estoy cansado; aun así, quiero seguir estudiando español.
Hoy estoy cansado; sin embargo, quiero seguir estudiando español.
Aunque hoy estoy cansado, quiero seguir estudiando español.

All are correct, but the structure changes.

Why aun without an accent? What is the difference between aun and aún?

The accent changes the meaning:

aún (with accent) ≈ todavía (still, yet):
- Aún estoy cansado. = I am still tired.
aun (without accent) ≈ incluso / hasta (even):
- Aun cansado, estudio. = Even tired, I study.
- aun así = even so.

In the fixed expression aun así, it always means even so, so it is written aun without an accent:

Hoy estoy cansado; aun así, quiero seguir estudiando español.

Why is it quiero seguir estudiando and not just quiero estudiar?

Both are correct, but they express slightly different ideas:

Quiero estudiar español.
- I want to study Spanish (no particular idea of continuity).
Quiero seguir estudiando español.
- seguir + gerundio means to continue / keep on doing something.
- So this is I want to keep (on) studying Spanish or I want to continue studying Spanish.

In your sentence, seguir estudiando emphasizes that you have already been studying and you want to go on, despite being tired.

Why is it seguir estudiando (gerund) and not seguir estudiar (infinitive)?

With seguir, when you want to say to continue doing something, Spanish uses:

seguir + gerundio (the -ando / -iendo form), not the infinitive.

Examples:

Sigo trabajando. = I keep working.
Sigue lloviendo. = It is still raining / It keeps raining.
Quiero seguir estudiando español. = I want to keep studying Spanish.

So seguir estudiar is incorrect in this meaning; it must be seguir estudiando.

Why is español not capitalized here?

In Spanish, names of languages are written with a lowercase initial letter:

el español, el inglés, el francés, el alemán

They are only capitalized if they start a sentence or are part of a title. So:

Quiero seguir estudiando español. ✅
Quiero seguir estudiando Español. ❌ (incorrect in normal text)

Can hoy go in another position, like Estoy cansado hoy? Does the meaning change?

Yes, hoy is quite flexible. These are all natural:

Hoy estoy cansado. (Very common; slight emphasis on “today”.)
Estoy cansado hoy. (Also correct; a bit more neutral-sounding.)
Hoy estoy cansado; aun así, quiero seguir estudiando español.
Estoy cansado hoy; aun así, quiero seguir estudiando español.

The overall meaning is the same: you’re tired today. Hoy often goes at the beginning of the sentence to set the time frame.

Why is there no yo in (Yo) estoy cansado? When would I include it?

Spanish usually omits subject pronouns because the verb ending already shows the person:

Estoy cansado. (The -oy ending of estoy already tells us it’s yo.)
Quiero seguir estudiando español. (The -o ending of quiero also indicates yo.)

You include yo when you want to emphasize or contrast:

Yo estoy cansado, pero tú no.
Hoy yo estoy cansado; normalmente no lo estoy.

In your sentence, there’s no special emphasis on I, so omitting yo is the most natural choice.

In Spain, do people usually say español or castellano for the language?

Both are used in Spain, but usage varies by region and context:

español – the most international and widely recognized term for the language.
castellano – often used in Spain, especially:
- In contrast with other official languages (Catalan, Basque, Galician).
- In more formal or institutional contexts (e.g., Lengua Castellana y Literatura as a school subject).

In your sentence, both are possible:

… seguir estudiando español. (most common, completely standard)
… seguir estudiando castellano. (also correct, heard often in Spain)

For learners, español is usually the safest and most widely understood option.