Learn Hardcore Spanish (Spain): Antes del examen, mi amiga está tan ansiosa que casi no duerme. - Before the exam, my friend is so anxious that she hardly sleeps.

When antes del examen is at the beginning, Spanish usually uses a comma after it.
When it’s at the end, you normally don’t put a comma before it in this type of simple sentence.

Why is it está tan ansiosa and not es tan ansiosa?

Estar describes temporary states, moods, or conditions.
Ser describes more permanent or defining characteristics.

Mi amiga está tan ansiosa… → She is anxious right now / in this situation (before the exam).
Mi amiga es ansiosa. → She is an anxious person in general, as part of her character.

Here we’re talking about how she feels before the exam, so está is the natural choice.

Does ansiosa just mean “nervous,” or can it mean “eager” too?

Ansiosa can mean:

Nervous / anxious / worried
- Very common in this context with an exam: tension, worry, stress.
Eager / excited (impatient to do something)
- Está ansiosa por verte. = She can’t wait to see you.

In Spain, for exam stress, nerviosa is actually more common in everyday speech:

Antes del examen, mi amiga está tan nerviosa que casi no duerme.

Ansiosa here is still correct and clear; it just sounds a bit closer to “anxious” than “just nervous.”

Why does it say mi amiga está tan ansiosa and not mi amigo está tan ansioso?

Spanish adjectives agree in gender and number with the noun they describe.

amiga is feminine → ansiosa (feminine form)
amigo would be masculine → ansioso

So:

Mi amiga está ansiosa. (female friend)
Mi amigo está ansioso. (male friend)
Mis amigos están ansiosos. (group of male or mixed friends)
Mis amigas están ansiosas. (group of female friends)

What does tan ... que mean exactly, and how is it used?

Tan … que means “so … that” and introduces a consequence:

tan + adjective/adverb + que + result

In the sentence:

tan ansiosa → so anxious
que casi no duerme → that she almost doesn’t sleep

More examples:

Estoy tan cansado que me duermo de pie.
I’m so tired that I fall asleep standing up.
Habla tan rápido que no le entiendo.
He speaks so fast that I don’t understand him.

Don’t confuse tan with tanto:

tanto + noun: so much / so many (e.g. tanto trabajo, tantos problemas)
tan + adjective/adverb: so + adj/adv (e.g. tan grande, tan rápidamente)

Why is it que casi no duerme and not a subjunctive like que casi no duerma?

The structure tan … que … introduces a real consequence, not a wish, doubt, or unreality. So Spanish uses the indicative:

que casi no duerme (she actually hardly sleeps)

The subjunctive duerma would appear if the clause expressed something non-factual, like:

Quiero que casi no duerma. (I want her to almost not sleep — odd, but grammatically a wish → subjunctive)

In this sentence we’re simply describing what happens, so duerme (indicative) is correct.

What’s the difference between casi no duerme and casi duerme?

They mean very different things:

Casi no duerme → She hardly sleeps / almost doesn’t sleep.
(Very little sleep.)
Casi duerme → She almost sleeps / is on the verge of sleeping.
(She’s about to fall asleep, but not quite.)

So the position of no completely changes the meaning. In the sentence, casi no duerme is the standard way to say she hardly sleeps.

Could you say apenas duerme instead of casi no duerme?

Yes. Apenas duerme also means she hardly sleeps and is very natural in Spain:

Antes del examen, mi amiga está tan ansiosa que apenas duerme.

Nuance:

casi no duerme = almost doesn’t sleep
apenas duerme = scarcely / barely sleeps

In everyday conversation they’re very close in meaning, and both are used.

Why is it duerme and not dormir or está durmiendo?

duerme is the present indicative, 3rd person singular of dormir → she sleeps.
Spanish often uses this simple present where English might say “she sleeps” or “she is sleeping” to talk about general or repeated behavior.
dormir is the infinitive → to sleep; it wouldn’t fit as the main verb here.
está durmiendo is present progressive → she is sleeping (right now).
That would describe what is happening at this exact moment, which is not the idea here. We’re talking about what generally happens when she’s anxious before the exam.

So casi no duerme is the natural way to describe this habitual or typical result.

Where is the word “she”? Why don’t we see ella?

Spanish usually omits subject pronouns when the verb ending already shows the subject:

duerme could be he sleeps, she sleeps, or you (formal) sleep, depending on context.
In this sentence, the subject is already clear: mi amiga.
So there’s no need to add ella.

You could say:

Antes del examen, mi amiga está tan ansiosa que ella casi no duerme.

But in normal Spanish this sounds redundant and is only used for emphasis or contrast (e.g. mi amiga casi no duerme, pero yo sí).

Why does está have an accent, but examen doesn’t?

Spanish accents (tildes) mark the stressed syllable when it doesn’t follow the normal stress rules.

está
- Ending in vowel → normally stressed on the second-to-last syllable
- But we need stress on the last syllable: es‑TÁ
- So it takes an accent: está
examen
- Ends in n → normally stressed on the second-to-last syllable
- Stress is on XA: e‑XA‑men → second-to-last
- It follows the rule, so no accent: examen

Note: the plural exámenes does get an accent, because the stress moves: e‑XA‑me‑nes → XA is now the third-to-last syllable, so we mark it: exámenes.