Learn Hardcore Spanish (Spain): Hoy estoy medio cansado, pero quiero estudiar español. - Today I am kind of tired, but I want to study Spanish.

Estoy cansado = I am tired (right now / today / at the moment)
Soy cansado would sound like I am a tiring person / I am someone who tends to be tired (and is usually incorrect in this context).

Because being tired here is a temporary state, estar is the correct verb.

What does medio cansado mean, and how is it different from un poco cansado?

Both mean something like a bit / kind of tired, but there is a small nuance:

un poco cansado = a little tired (neutral, very common)
medio cansado = kind of tired, somewhat tired; often feels a bit more colloquial or informal, like half tired, sort of tired.

In Spain, you will hear un poco cansado more often in standard speech, but medio cansado is also used and understood.

Why is it medio cansado and not media cansado?

Here medio works as an adverb meaning kind of / somewhat, not as an adjective meaning half.

As an adjective, medio agrees:
- media naranja (half an orange)
- medios días (half days)
As an adverb, medio does not change:
- medio cansado (kind of tired – masculine)
- medio cansada (kind of tired – feminine)

So in this sentence medio is invariable because it is modifying the adjective cansado as an adverb.

If I am a woman, should I say cansado or cansada?

If you are a woman, you should say cansada:

Man: Hoy estoy medio cansado.
Woman: Hoy estoy medio cansada.

The adjective cansado / cansada must agree in gender with the speaker.
Remember medio stays the same (see previous answer): medio cansado, medio cansada.

Can I move hoy or medio around, like Estoy hoy medio cansado or Hoy medio estoy cansado?

Some movements are natural, others sound odd.

Most natural options:

Hoy estoy medio cansado. (original, very natural)
Estoy medio cansado hoy. (also natural)
Hoy estoy un poco cansado. (if you use un poco)
Estoy un poco cansado hoy.

Options that sound strange or incorrect in normal speech:

Hoy medio estoy cansado. (odd word order)
Estoy hoy medio cansado. (possible but sounds clumsy / overly marked)

As a rule, keep hoy at the beginning or the end of the clause, and keep medio directly before cansado.

Why is there a comma before pero? Is it necessary?

Yes, in written Spanish it is standard to put a comma before pero when it introduces a contrast between two clauses:

Hoy estoy medio cansado, pero quiero estudiar español.

The comma shows a pause and separates the two ideas:
1) I am kind of tired.
2) I still want to study Spanish.

In very informal writing (texts, WhatsApp) some people skip it, but the correct written form includes the comma.

What is the difference between pero and sino?

Both can translate as but, but they are used differently.

pero = but, adds or contrasts information:
- Estoy cansado, pero quiero estudiar.
  I am tired, but I want to study.
sino = but rather / but instead, corrects a previous negative:
- No quiero descansar, sino estudiar.
  I do not want to rest, but rather to study.

In your sentence the first part is not negative, so you must use pero, not sino.

Why is it quiero estudiar and not quiero a estudiar?

In Spanish, verbs like querer, poder, deber, saber (meaning to know how) are followed directly by an infinitive without a preposition:

Quiero estudiar. (I want to study.)
Puedo estudiar. (I can study.)
Debo estudiar. (I must study.)
Sé estudiar solo. (I know how to study on my own.)

Using a here (quiero a estudiar) is incorrect; it is interference from English.

Why is español written with a lowercase e, not capitalized like Spanish?

In Spanish:

Names of languages are written with a lowercase letter:
- español, inglés, francés, alemán
Nationalities are also lowercase:
- soy español, soy inglesa

So quiero estudiar español is correct. Capital Español would normally be considered a spelling mistake (except at the beginning of a sentence or in a title).

Could I say quiero estudiar el español instead of quiero estudiar español?

You can say quiero estudiar el español, and it is grammatically correct, but there is a nuance:

quiero estudiar español
= I want to study Spanish (the language in general; this is the usual, natural way).
quiero estudiar el español
= I want to study the Spanish language (slightly more specific or formal, like referring to the language as an object of study, for example in linguistics or in a course title).

In everyday conversation, quiero estudiar español is the normal choice.

Why is hoy used instead of something like este día?

In Spanish, hoy is the natural, common word for today.

hoy = today
este día = this day (more literal, and sounds unusual or overly formal in this context)

If you simply mean today, you should always use hoy:

Hoy estoy cansado. (Today I am tired.)

Could I say Hoy estoy un poco cansado instead of medio cansado? Does it change the meaning?

Yes, you can, and it is very natural:

Hoy estoy un poco cansado, pero quiero estudiar español.

Meaning difference:

un poco cansado = a little tired, slightly tired (neutral)
medio cansado = kind of tired, somewhat tired (often feels a bit more colloquial or expressive)

In most situations, un poco cansado is the safest, most standard option; medio cansado just adds a slightly more informal flavor.

Why is the present tense quiero estudiar used, and not a future form like estudiaré or voy a estudiar?

Spanish often uses the present tense to talk about current intentions or plans, especially if they are relatively immediate or general:

Quiero estudiar español.
I want to study Spanish (now / in general / starting now).

Other options:

Voy a estudiar español.
I am going to study Spanish (a more explicit future plan).
Estudiaré español.
I will study Spanish (more formal or more distant future, or a decision in that moment).

In your sentence, quiero estudiar focuses on the desire or intention rather than fixing a specific future moment.

Why is there no yo before estoy and quiero? Would saying Yo hoy estoy medio cansado be wrong?

Spanish normally omits subject pronouns (yo, tú, él, etc.) because the verb ending already shows who the subject is:

Estoy medio cansado. = I am kind of tired.
Quiero estudiar. = I want to study.

Adding yo is possible, but it usually adds emphasis:

Yo hoy estoy medio cansado, pero quiero estudiar español.
Sounds like: Me, today I’m kind of tired, but I want to study Spanish.

So the version without yo is more natural and neutral in this context.

Is there any pronunciation tip for hoy, estoy, quiero, and español?

Key points:

hoy: the h is silent. It sounds like oy (similar to English oy in boy, but shorter).
estoy: stress on -toy → es-TOY.
quiero: qui is like kee, but a bit shorter; quie- sounds like kyeh; stress on -e- → KYE-ro.
español: stress on the last syllable -ñol → es-pa-ÑOL. The ñ is like ny in canyon.

Also, every vowel is clearly pronounced; there are no reduced vowels like the English uh sound in sofa.