Estou doente hoje.

Because Portuguese usually uses estar for temporary states or conditions, and being sick is normally treated as temporary.

• estou = I am from estar
• sou = I am from ser

So:

• Estou doente hoje. = I’m sick today.
• Sou doente. would sound very odd in most situations, because it suggests sickness as a defining or permanent characteristic rather than a temporary condition.

A very common learner rule is:

• ser = more permanent/essential
• estar = more temporary/current

That rule is not perfect in every case, but it works very well here.

Portuguese often leaves out the subject pronoun when the verb already shows who the subject is.

• estou already means I am
• So Eu estou doente hoje and Estou doente hoje both mean the same thing

In everyday Portuguese, especially in Brazil, dropping eu is very common when the meaning is clear.

You might include eu for emphasis, contrast, or clarity:

• Eu estou doente hoje, mas ele está bem.
  I’m sick today, but he’s fine.

Doente means sick, ill, or unwell.

In this sentence, it describes a physical condition. Depending on context, it can mean:

• physically sick
• ill in general
• not feeling well

It is an adjective here.

Related words:

• doença = illness, disease
• adoecer = to become sick
• enfermo = ill/sick, but more formal or less common in everyday Brazilian speech

For normal conversation in Brazil, doente is very natural.

Doente is an adjective that has the same form for both masculine and feminine in the singular.

• Ele está doente. = He is sick.
• Ela está doente. = She is sick.

In the plural, it becomes:

• Eles estão doentes.
• Elas estão doentes.

So the pattern is:

• singular: doente
• plural: doentes

Yes, hoje can move around. It means today, and Portuguese allows some flexibility with adverbs like this.

These are all possible:

• Estou doente hoje.
• Hoje estou doente.
• Hoje, estou doente.

The most neutral version here is Estou doente hoje.

Putting hoje first can give it slightly more emphasis:

• Hoje estou doente.
  As for today, I’m sick.

So the meaning stays basically the same, but the focus can shift a little.

A rough pronunciation for an English speaker is:

• es-TOH do-EN-che OH-zhee

A few important points:

• estou sounds roughly like es-TOH
• doente has three syllables: do-en-te
• In many Brazilian accents, the final te sounds like chee, so doente may sound like do-EN-che
• hoje is roughly OH-zhee in many Brazilian accents

A more approximate Brazilian pronunciation in IPA is:

• [isˈtow dwiˈẽtʃi ˈoʒi] or similar, depending on accent

Brazilian pronunciation varies by region, so don’t worry if you hear small differences.

Yes. Tô is a very common spoken contraction of estou in Brazilian Portuguese.

So:

• Estou doente hoje. = neutral, full form
• Tô doente hoje. = very common in informal speech

This is extremely natural in conversation. In more formal writing, estou is better.

Usually hoje means today, but like English today, it can sometimes be used a bit loosely depending on context.

In Estou doente hoje, the basic idea is:

• right now / today, I’m sick

It does not necessarily mean only today and not yesterday or tomorrow. It simply places the situation in today’s time frame.

So the sentence can mean:

• I’m sick today.
• I’m feeling ill today.

Not by itself. Estou doente hoje is general.

It means something like:

• I’m sick today
• I’m ill today
• I’m not well today

If you want to be more specific, Portuguese usually says that directly:

• Estou com gripe. = I have the flu.
• Estou resfriado / resfriada. = I have a cold.
• Estou com febre. = I have a fever.
• Estou enjoado / enjoada. = I feel nauseous.

So doente is broad, not specific.

Doente is completely natural, but depending on the situation, Brazilians might also say:

• Estou mal hoje. = I feel bad / unwell today.
• Não estou me sentindo bem hoje. = I’m not feeling well today.
• Tô passando mal. = I’m feeling sick / unwell, often more immediate or intense

The nuance is:

• doente = sick/ill in a general sense
• mal = feeling bad/unwell
• não estou me sentindo bem = softer, very common, polite
• passando mal = more like actively feeling unwell

So Estou doente hoje is correct and natural, but in real conversation, people often choose among several options.

Yes, absolutely. Eu estou doente hoje is correct.

For beginners, including the subject can be helpful because it makes the structure clearer:

• Eu = I
• estou = am
• doente = sick
• hoje = today

But native speakers often omit eu when it is obvious.

So both are good:

• Eu estou doente hoje.
• Estou doente hoje.

The second one sounds a bit more natural in many everyday situations.

Estou is the first-person singular present tense form of estar.

The present tense of estar is:

• eu estou = I am
• você / ele / ela está = you are / he is / she is
• nós estamos = we are
• vocês / eles / elas estão = you all are / they are

So in the sentence:

• Estou doente hoje.

the hidden subject is eu.

Yes, it sounds natural and correct.

A Brazilian speaker would understand it immediately. It is a simple, everyday sentence.

That said, in casual speech, many Brazilians would very often say:

• Tô doente hoje.
• Não tô me sentindo bem hoje.
• Tô mal hoje.

But Estou doente hoje is still perfectly normal and clear.