Antes del examen oral, puedo empezar a temblar si estoy muy nerviosa.

Because del is the mandatory contraction of de + el in Spanish.

• de + el = del
• So antes de el examen is incorrect.
• The full phrase is antes de + el examen oral = antes del examen oral

A similar example:

• vengo del colegio = de el colegio is not used

One important exception: if El is part of a proper name, you do not contract it.

• de El Escorial ✅

Antes de means before.

In this sentence, it is followed by a noun phrase:

• antes del examen oral = before the oral exam

Spanish uses:

• antes de + noun
• antes de + infinitive

Examples:

• antes del examen = before the exam
• antes de salir = before leaving

So here, because examen oral is a thing/event, Spanish uses antes de plus the noun phrase.

In Spanish, adjectives usually come after the noun, unlike in English.

So:

• examen oral = oral exam
• literally: exam oral

This is the normal word order for most descriptive adjectives in Spanish.

More examples:

• casa grande = big house
• libro interesante = interesting book

Sometimes adjectives can go before the noun, but that usually changes the tone or emphasis. In this case, examen oral is the standard and natural order.

Because empezar is commonly followed by a + infinitive when it means to start/begin doing something.

So:

• empezar a temblar = to start trembling
• empezar a hablar = to start speaking
• empezar a estudiar = to start studying

This is just the normal pattern:

• empezar a + infinitive

Without the a, it would sound ungrammatical here.

Literally, puedo means I can. But in context, it often expresses possibility, so in natural English it may be translated more like I might or I can end up.

So puedo empezar a temblar suggests:

• I can start trembling
• or more naturally in context, I might start trembling

Spanish poder often covers both ability and possibility, and context tells you which one is meant.

Because after empezar a, Spanish uses the infinitive, not the gerund.

So:

• empezar a temblar ✅
• empezar a temblando ❌

The infinitive is the dictionary form of the verb:

• temblar = to tremble

The gerund temblando means trembling, but it is used in different structures, for example:

• Estoy temblando = I am trembling

Because estar nerviosa refers to a temporary emotional state, while ser nerviosa describes a more general personality trait.

In this sentence, the speaker means they are nervous at that moment / in that situation, so Spanish uses estar:

• estoy muy nerviosa = I am very nervous

Compare:

• Soy nerviosa = I am a nervous person / I tend to be nervous
• Estoy nerviosa = I am nervous right now

Since the sentence is about what happens before an exam, estar is the correct choice.

Because the speaker is female, or the sentence is being said from a feminine perspective.

Spanish adjectives usually agree in gender and number with the person they describe:

• nervioso = masculine singular
• nerviosa = feminine singular

So:

• a man would say estoy muy nervioso
• a woman would say estoy muy nerviosa

If you do not know the speaker’s gender, the sentence itself tells you it is feminine because of nerviosa.

Because muy is the word used to modify adjectives and adverbs, and nerviosa is an adjective.

So:

• muy nerviosa = very nervous

Use muy before:

• adjectives: muy difícil
• adverbs: muy rápido

Use mucho/mucha/muchos/muchas mostly with nouns, or as an adverb in some cases:

• mucha hambre = a lot of hunger
• mucho trabajo = a lot of work

So muy nerviosa is the correct form here.

Yes. Here si means if and introduces a real or possible condition.

So:

• si estoy muy nerviosa = if I am very nervous

Because this is a likely or real condition, Spanish uses the present indicative:

• si estoy...
• si tengo tiempo...
• si hace frío...

This is different from more hypothetical structures involving the imperfect subjunctive, such as:

• si estuviera muy nerviosa... = if I were very nervous...

But in your sentence, the speaker is talking about a realistic situation, so si estoy is exactly right.

Because Antes del examen oral is an introductory time phrase placed at the beginning of the sentence.

The comma helps separate that opening phrase from the main clause:

• Antes del examen oral, puedo empezar a temblar...

In Spanish, this comma is very natural and often recommended for clarity, especially when the opening phrase is not very short. You may sometimes see similar phrases without a comma in informal writing, but here the comma is perfectly standard.

Yes, but the meaning changes slightly.

• puedo empezar a temblar = I can / might start trembling
  • this suggests possibility
• empiezo a temblar = I start trembling
  • this sounds more direct and factual

So the original sentence is a bit softer and more general: it says this is something that may happen when the speaker is very nervous, not that it always definitely happens.

Yes. Examen oral means an oral exam, that is, an exam where you answer by speaking rather than writing.

It contrasts with:

• examen escrito = written exam

So oral here does not mean about the mouth in a medical sense; it means spoken or done verbally, just like in English oral exam.