Ela é a única pessoa aqui.

Because ser is used for identification and inherent description, while estar is usually used for temporary states or location.

In Ela é a única pessoa aqui, the sentence is identifying who she is in relation to the group: she is the only person here. That calls for ser.

A few contrasts:

• Ela é médica. = She is a doctor.
• Ela está cansada. = She is tired.
• Ela está aqui. = She is here.

So even though aqui appears in the sentence, the main idea is not just location; it is identification: she is the only person present.

Portuguese often uses the definite article where English might not think about it as much. In this sentence, a única pessoa means the only person.

The article a is required because:

• pessoa is a feminine singular noun
• única agrees with pessoa
• the whole phrase means a specific identified person: the only person

So:

• a pessoa = the person
• a única pessoa = the only person

Because única is an adjective describing pessoa, and adjectives in Portuguese usually agree in gender and number with the noun they modify.

• pessoa is grammatically feminine
• singular noun → singular adjective
• so único becomes única

Examples:

• o único livro = the only book
• a única pessoa = the only person
• os únicos livros = the only books
• as únicas pessoas = the only people

No. Pessoa is always a grammatically feminine noun, even when referring to a man.

That means words agreeing with pessoa must be feminine:

• uma pessoa boa
• a única pessoa
• essa pessoa

But the real-life gender of the person can still be male or female.

For example:

• Ele é a única pessoa aqui. = He is the only person here.

This may feel strange to English speakers, but it is completely normal in Portuguese: the adjective/article agree with pessoa, not with the biological sex of the person being referred to.

Yes, Portuguese often allows the subject pronoun to be omitted because the verb form already gives information about the subject.

So these are both possible:

• Ela é a única pessoa aqui.
• É a única pessoa aqui.

However, ela is often included:

• for clarity
• for emphasis
• when contrasting with someone else
• when context does not make the subject obvious

For example:

• Ela é a única pessoa aqui, não ele. = She is the only person here, not him.

Aqui means here.

Putting it at the end is the most natural word order in this sentence:

• Ela é a única pessoa aqui.

It modifies the whole idea of the situation/location: she is the only person here.

Portuguese often places adverbs like aqui after the main noun phrase or later in the sentence. Other positions are possible in some contexts, but this version is the most standard and natural.

Yes, if the noun pessoa is understood from context.

• Ela é a única pessoa aqui. = full version
• Ela é the only one here. = more compact version

In Portuguese:

• Ela é a única aqui.

This sounds natural when everyone already knows you are talking about people. But if you want to be explicit or careful, a única pessoa is clearer.

Not in exactly the same way.

• Ela é a única pessoa aqui. = She is the only person here.
• Ela apenas/só está aqui. = She is only just here / She is simply here / only she is here, depending on context.

Única expresses uniqueness: there is no other person here. Words like só, somente, and apenas express only, but they do not automatically create the noun phrase the only person.

You could say:

• Só ela está aqui. = Only she is here.
• Ela é a única que está aqui. = She is the only one who is here.

These are related, but not identical in structure.

É is the 3rd person singular form of ser in the present tense: he/she/it is.

The accent mark in é shows that the vowel is stressed and helps distinguish it from e, which means and.

So:

• é = is
• e = and

Pronunciation:

• é sounds roughly like eh, with an open vowel

This accent is very important because it changes both pronunciation and meaning.

Yes. That sentence is correct, but the emphasis changes.

• Ela é a única pessoa aqui. → neutral, starting with she
• A única pessoa aqui é ela. → more emphasis on she as the identified person

This second version can sound more contrastive, like:

• The only person here is her.

It is often used when clarifying or pointing someone out.

The most natural order is:

• Ela é a única pessoa aqui.

But Portuguese allows some flexibility depending on emphasis.

Possible alternatives:

• A única pessoa aqui é ela.
• Aqui, ela é a única pessoa. — possible, but less neutral
• Ela é aqui a única pessoa. — unnatural in normal speech

So for a learner, the standard version is the best one to use.

If you wanted to say They are the only people here, the sentence would be:

• Elas são as únicas pessoas aqui.
• Eles são as únicas pessoas aqui.

Notice the changes:

• é → são
• a → as
• única → únicas
• pessoa → pessoas

Also note something important: If you use pessoas, the phrase as únicas pessoas stays feminine because pessoas is feminine, even if eles refers to men or a mixed group.

It is neutral and completely natural in both spoken and written Brazilian Portuguese.

It works in:

• everyday conversation
• descriptions
• written text
• formal and informal contexts

It is a very standard sentence pattern, so it is a good model to learn:

• [Subject] + é + a/o único(a) + noun + aqui/ali/lá

For example:

• Ele é o único aluno aqui.
• Ela é a única professora aqui.
• Este é o único problema aqui.