Hoje estou nervoso por causa de um exame.

Today I am nervous because of an exam.

Breakdown of Hoje estou nervoso por causa de um exame.

• hoje: today
• um: a
• estar: to be
• o exame: the exam
• nervoso: nervous
• por causa de: because of

Questions & Answers about Hoje estou nervoso por causa de um exame.

Why is it estou nervoso and not sou nervoso?

Portuguese has two verbs for “to be”: ser and estar.

• estar is for temporary states, feelings, locations, and things that can change:

  • Hoje estou nervoso. – Today I am nervous (right now).
  • Estou cansado. – I am tired.

• ser is for permanent or defining characteristics, professions, time, nationality, etc.:

  • Sou alto. – I am tall.
  • Sou português. – I am Portuguese.

Being nervous because of an exam is clearly a temporary emotional state, so you must use estar:
Hoje estou nervoso. is correct; Hoje sou nervoso. would sound wrong or very strange in Portuguese.

Why does it say nervoso and not nervosa? What changes if the speaker is a woman?

Adjectives in Portuguese agree in gender and number with the noun (or pronoun) they refer to.

Here, nervoso refers to eu (I). If the speaker is:

• Male:

  • Hoje estou nervoso.

• Female:

  • Hoje estou nervosa.

For plural:

• Group of only men / mixed group:

  • Hoje estamos nervosos. – Today we are nervous.

• Group of only women:

  • Hoje estamos nervosas.

So -o → masculine; -a → feminine, in this kind of adjective.

Is the word order fixed? Can I say “Estou nervoso hoje por causa de um exame”?

The word order is flexible. All of these are grammatically correct and natural:

• Hoje estou nervoso por causa de um exame.
• Estou nervoso hoje por causa de um exame.
• Estou nervoso por causa de um exame hoje.

Differences are mostly about emphasis:

• Starting with Hoje gives more weight to “today” (today, specifically, I’m nervous).
• Putting hoje later is more neutral or focuses more on the state “estou nervoso”.

In everyday speech, all three versions can be heard; the original one is slightly more common and neat-sounding.

What exactly does por causa de mean? Could I use porque instead?

por causa de literally means “because of / due to” and is followed by a noun phrase:

• por causa de um exame – because of an exam
• por causa da chuva – because of the rain

porque means “because” and is followed by a clause (a full sentence):

• Estou nervoso porque tenho um exame.
  I’m nervous because I have an exam.

You cannot just replace one with the other:

• ✔ Estou nervoso por causa de um exame.
• ✔ Estou nervoso porque tenho um exame.
• ✘ Estou nervoso porque um exame.
• ✘ Estou nervoso por causa de tenho um exame.

So:

• por causa de + noun
• porque + verb (a full sentence)

Why is it por causa de um exame and not just por um exame?

por um exame would be grammatically possible but sounds odd or incomplete in this context.

• por causa de explicitly expresses reason / cause: “because of / due to”.
• por alone has many meanings: by, through, for, per, because of, etc., but on its own here it doesn’t clearly sound like “because of”.

Native speakers almost always say:

• Estou nervoso por causa de um exame.
  or
• Estou nervoso por causa do exame.

Using only por (Estou nervoso por um exame) is technically understandable, but it’s not natural in modern European Portuguese for this meaning.

Why is it um exame and not o exame? What’s the difference?

Portuguese uses indefinite and definite articles like English:

• um exame = an exam (not specified which one, or it’s being introduced for the first time)
• o exame = the exam (both speakers know which exam they are talking about)

So:

• Hoje estou nervoso por causa de um exame.
  Today I’m nervous because of an exam (some exam, you’re introducing it).

• Hoje estou nervoso por causa do exame de matemática.
  Today I’m nervous because of the maths exam (a specific, known exam).

Both are correct; it just depends on whether the exam is already specific/known in context.

I’ve seen dum exame in writing. Is por causa dum exame also correct?

Yes. In European Portuguese, de + um can contract to dum:

• por causa de um exame → por causa dum exame

Both mean exactly the same. Differences:

• de um – a bit more neutral / formal, very common in writing.
• dum – very common in speech and informal writing.

So for Portugal:

• ✔ Hoje estou nervoso por causa de um exame.
• ✔ Hoje estou nervoso por causa dum exame.

Why is there no eu? Can I say Eu hoje estou nervoso…?

Portuguese is a “pro-drop” language, meaning subject pronouns (eu, tu, ele, nós, etc.) are often omitted because the verb ending already shows who the subject is.

• estou can only mean “I am” → the eu is understood.
• So Hoje estou nervoso… is perfectly complete.

You can say Eu hoje estou nervoso…, but then eu is usually added for:

• emphasis:
  
  • Eu hoje estou nervoso, não tu.
• contrast:
  
  • Eu estou nervoso, mas ela está calma.

In a simple sentence like yours, the natural version is without eu.

How do you pronounce Hoje estou nervoso por causa de um exame in European Portuguese?

Approximate European Portuguese pronunciation (Lisbon-like):

• Hoje – [ˈoʒɨ]
  
  • Starts like “o” in “order” (shorter), then a sound like the “s” in “measure” (ʒ), and a final reduced vowel ɨ (like a very quick, weak “uh”).
• estou – [(ɨ)ʃˈto(w)]
  
  • Often sounds like “shtoh”. The first vowel may be almost silent.
• nervoso – [nɨɾˈvozu]
  
  • r is a tap, like Spanish r in “pero”.
• por – [poɾ] (often with a light tap r)
• causa – [ˈkawzɐ]
  
  • au = “ow” in “cow”, s → z sound between vowels.
• de – [dɨ] (reduced vowel, like weak “duh”)
• um – [ũ] (nasal “oo”, like saying “oo” while letting air pass through your nose)
• exame – [(ɨ)ˈzɐm(ɨ)]
  
  • In European Portuguese, many speakers say something close to “iz-uhm(uh)”, with a soft z.

Spoken quickly, it can sound like:

[ˈoʒɨ ʃˈto nervˈozu poɾ ˈkawzɐ dũ iˈzɐmɨ]
Roughly: “Ozh shtoh nervozo por kowza dũ izam(uh)”

Is this sentence also correct in Brazilian Portuguese, or is it specific to Portugal?

The sentence is perfectly correct in Brazilian Portuguese too:

• Hoje estou nervoso por causa de um exame.

In Brazil, people might also often say:

• Hoje estou nervoso por causa de uma prova. (prova = test/exam)
• or por causa do vestibular / concurso, etc., for specific exam types.

The structure Hoje estou nervoso por causa de… is fine in both European and Brazilian Portuguese. The vocabulary choice for “exam” (exame, prova, etc.) can vary by country and context.

What’s the difference between exame, teste, and prova?

In European Portuguese (Portugal), broadly:

• exame

  • Often a formal or important exam, especially at the end of a course or for national exams.
  • exame de condução – driving test.
  • exame nacional – national exam.

• teste

  • A more regular test, usually in school during the term.
  • Tenho um teste de matemática amanhã. – I have a maths test tomorrow.

• prova

  • Can also mean test/exam, but it’s a bit broader:
    • a test in school,
    • a trial, a competition event, a tasting (e.g. prova de vinhos = wine tasting).

In your sentence, exame suggests an important or formal exam, which fits well with feeling nervous.

Could I say “Hoje fico nervoso por causa de um exame” instead of “Hoje estou nervoso…”? What’s the difference?

Yes, but the meaning changes slightly.

• Hoje estou nervoso por causa de um exame.
  → Right now / today, I am (in a state of being) nervous because of an exam.

• Hoje fico nervoso por causa de um exame.
  → Today I get / become nervous because of an exam.
  This sounds more like describing a reaction or process, or even a habit if said in the present tense without context:
  “When there’s an exam, I (tend to) get nervous.”

So:

• Use estou nervoso to talk about your current state.
• Use fico nervoso to talk about becoming nervous or a typical reaction.