Learn Hardcore Croatian: Večeras sam umoran i jedva učim hrvatski. - Tonight I am tired and I am barely studying Croatian.

Večeras sam umoran i jedva učim hrvatski. – literally: Tonight I am tired and I hardly study Croatian.
You can also say: Ja sam večeras umoran i jedva učim hrvatski.
Or: Večeras jedva učim hrvatski jer sam umoran.

Putting večeras at the beginning is very natural and slightly emphasizes when this is happening. You could also say:

Umoran sam večeras i jedva učim hrvatski.

All of these are grammatical; the differences are mostly in emphasis and style, not correctness.

What exactly does večeras mean? Is it “this evening” or “tonight”? How is it different from noćas?

Večeras literally means “this evening” (from večer = evening).

In practice:

večeras – this evening, the time before night, roughly early night hours (when people are still active).
noćas – tonight, during the night, usually when people would normally be sleeping.

They can overlap a bit in casual speech (people sometimes use them loosely), but:

I’m going out for a drink this evening. → Večeras izlazim.
I couldn’t sleep tonight. → Noćas nisam mogao/mogla spavati.

Why is there no “ja” (“I”) in the sentence? Can I say “Ja večeras sam umoran”?

In Croatian, the subject pronoun (ja = I, ti = you, etc.) is usually omitted because the verb (or auxiliary) already shows the person:

sam = I am
si = you are
je = he/she/it is

So Večeras sam umoran clearly means “Tonight I am tired.”

You can use ja for emphasis:

Ja sam večeras umoran. – I am tired tonight (as opposed to someone else / or in contrast to another time).

But Ja večeras sam umoran is unnatural; the clitic sam doesn’t like to be pushed to the end like that. Better options:

Ja sam večeras umoran.
Ja večeras jedva učim hrvatski.

What is sam exactly, and why is it needed?

Sam is the first person singular present tense of the verb biti (to be):

ja sam – I am
ti si – you are
on/ona/ono je – he/she/it is

So sam is equivalent to “am” in English.

In standard Croatian, you need this auxiliary in the present tense when you say “I am X”:

(Ja) sam umoran. – I am tired.
Not just Ja umoran in standard language (although you might hear it colloquially for emphasis or in very informal speech).

Why is it umoran and not something else? How would it change if a woman said this?

Umoran is an adjective meaning “tired”, and it agrees in gender and number with the subject.

Masculine singular: umoran
Feminine singular: umorna
Neuter singular: umorno
Masculine plural: umorni
Feminine plural: umorne
Neuter plural: umorna

So:

A man would say: Večeras sam umoran.
A woman would say: Večeras sam umorna.

The sentence in full for a female speaker:

Večeras sam umorna i jedva učim hrvatski.

Why is sam placed between večeras and umoran? Can I say Večeras umoran sam?

Sam is a clitic (short, unstressed word), and Croatian clitics normally go in the second position in the clause.

In Večeras sam umoran:

Večeras – first stressed element
sam – clitic in second position
umoran – rest of the predicate

This is the standard placement.

You can say Umoran sam večeras. – then:

Umoran – first stressed element
sam – clitic in second position
večeras – time adverb

Večeras umoran sam is technically possible in very marked, poetic, or strongly emphatic speech, but it sounds unnatural in everyday language. For normal speech, keep sam in the second position of the clause.

What does jedva mean exactly? Is it more like “barely,” “hardly,” or “with difficulty”?

Jedva can correspond to all of these English ideas, depending on context:

barely / hardly – almost not
with difficulty – requiring a lot of effort

In this sentence:

jedva učim hrvatski ≈ I’m barely managing to study Croatian / I can hardly study Croatian.

It suggests that because you’re tired, studying Croatian is difficult and you’re not doing much of it.

Why is it jedva učim and not učim jedva? Can jedva go somewhere else?

The default and most natural position for jedva is directly before the verb it modifies:

jedva učim hrvatski – I barely study Croatian.

You could move it:

Hrvatski jedva učim. – Emphasizes Croatian (“Croatian is what I can barely study”).
Jedva hrvatski učim. – Sounds odd or poetic; not typical everyday order.

For neutral, everyday speech, jedva + verb is the safest and most natural pattern:

Jedva hodam. – I can barely walk.
Jedva čekam. – I can hardly wait / I can’t wait.
Jedva govorim. – I can barely speak.

Why is učim used here? Does it mean “I learn” or “I am learning / studying”? Croatian doesn’t have a separate continuous tense, right?

Correct: Croatian does not have a separate present continuous tense like English (I am learning).

The same form učim (present tense of učiti) covers:

habitual/general: I learn / I study
- Svaki dan učim hrvatski. – I study Croatian every day.
progressive/ongoing right now: I am learning / studying
- Sada učim hrvatski. – I am studying Croatian now.

In Večeras sam umoran i jedva učim hrvatski, context (večeras, jedva) makes it clear that it’s about what is happening tonight, so you would translate it naturally as:

Tonight I’m tired and I’m hardly studying Croatian.

Why is hrvatski written with a lowercase letter? Isn’t it the name of a language?

In Croatian, names of languages are written with a lowercase letter, because they are treated as adjectives:

hrvatski – Croatian
engleski – English
njemački – German
španjolski – Spanish

You can think of učim hrvatski as an abbreviation of:

učim hrvatski jezik – I’m learning the Croatian language.

So English: Croatian (capital C)
Croatian: hrvatski (lowercase h).

Is hrvatski here a noun or an adjective, and what case is it in?

Grammatically, hrvatski is an adjective: “Croatian”.

However, in the phrase učim hrvatski, the noun jezik (“language”) is understood but omitted:

učim hrvatski (jezik) – I’m learning Croatian (language).

Because it is the direct object of učim, it is in the accusative singular masculine form:

nominative: hrvatski (jezik)
accusative: hrvatski (jezik)

For masculine inanimate nouns, nominative and accusative often look the same, and the adjective agrees with that.

Can I say “učim se hrvatski” instead of “učim hrvatski”?

No, not in standard usage for “I’m learning Croatian (the language).”

učim hrvatski – correct: I’m learning Croatian.
učim se – means I’m learning (myself) / I’m teaching myself and usually takes an infinitive:
- Učim se voziti. – I’m learning to drive.
- Učim se plivati. – I’m learning to swim.

For languages, you normally don’t use the reflexive se:

✅ Učim hrvatski.
❌ Učim se hrvatski. (unnatural / incorrect in this meaning)

Why is the conjunction i used here? Could you use a or pa instead?

I is the neutral “and” that simply adds another statement:

Večeras sam umoran i jedva učim hrvatski.
→ Tonight I am tired and I hardly study Croatian.

Alternatives:

a – often “and/but” with a contrast:
- Večeras sam umoran, a jedva učim hrvatski.
  – Slight feeling of contrast or “yet I hardly study”.
pa – can mean “and so / and then / so that”:
- Večeras sam umoran, pa jedva učim hrvatski.
  – I’m tired tonight, so I can hardly study Croatian.

In your sentence, i is the simplest and most neutral choice.