A vizinha foi reclamar porque ninguém conseguiu dormir durante a noite.

A means the, while uma means a/an.

So a vizinha refers to a specific neighbor the speaker has in mind, not just any neighbor.
Also, vizinha is the feminine form of vizinho, so it means female neighbor.

• a vizinha = the neighbor, specifically a woman
• uma vizinha = a neighbor, some woman neighbor

Vizinha means female neighbor. The masculine form is vizinho.

In everyday Brazilian Portuguese, it usually refers to someone who lives nearby, often in the same building, on the same street, or next door.

So:

• o vizinho = the male neighbor
• a vizinha = the female neighbor

Foi reclamar literally means went to complain.

This structure is:

• foi = went
• reclamar = to complain

Using foi reclamar adds the idea that she went somewhere or went to someone in order to complain.

Compare:

• A vizinha reclamou = The neighbor complained
• A vizinha foi reclamar = The neighbor went to complain

So the second version is a little more vivid and suggests action with purpose.

Yes. In Brazilian Portuguese, reclamar very often means to complain.

This is a common false friend for English speakers, because it looks like reclaim, but in most everyday situations it does not mean that.

Examples:

• Ela vive reclamando = She is always complaining
• Ele reclamou do barulho = He complained about the noise

In some contexts, reclamar can mean to demand or to claim, but the most common everyday meaning is to complain.

Because here it means because, introducing a reason.

Portuguese has several similar forms:

• porque = because
• por que = why / for what reason
• por quê = why, usually at the end of a question
• porquê = the reason, the why

In this sentence, the second part gives the reason she went to complain, so porque is the correct form.

Because ninguém already makes the clause negative.

Ninguém means nobody / no one, so ninguém conseguiu dormir already means nobody managed to sleep.

A useful rule:

• When a negative word like ninguém comes before the verb, you usually do not add não.
• When it comes after the verb, you usually do need não.

Compare:

• Ninguém chegou = Nobody arrived
• Eu não vi ninguém = I didn’t see anybody

So ninguém conseguiu is correct.

Because ninguém is grammatically singular.

Even though it refers to zero people in a group sense, Portuguese treats ninguém as a singular subject, so the verb stays singular:

• ninguém conseguiu
• not ninguém conseguiram

This is similar to how English uses nobody was rather than nobody were in standard grammar.

Conseguir + infinitive means to manage to do something, to succeed in doing something, or sometimes to be able to do something.

So ninguém conseguiu dormir means that nobody was able to sleep, or more literally, nobody managed to sleep.

It often suggests that something prevented the action.

Examples:

• Não consegui sair = I couldn’t manage to leave
• Ela conseguiu terminar = She managed to finish

Here, it implies that sleeping was attempted or desired, but did not happen successfully.

The preterite is used because the sentence talks about a completed situation in the past.

• foi reclamar = she went to complain
• ninguém conseguiu dormir = nobody managed to sleep

Both are presented as finished events.

A learner may also hear a version like:

• A vizinha foi reclamar porque ninguém conseguia dormir

That version uses the imperfect conseguia and gives more of a background sense: nobody could sleep / was able to sleep over that period.

So the difference is mostly about viewpoint:

• conseguiu = completed result
• conseguia = ongoing situation or background

They are close, but not the same.

• durante a noite = during the night
• à noite = at night, in the evening/nighttime

In this sentence, durante a noite emphasizes the span of time, almost like throughout the night.

Compare:

• Eu estudo à noite = I study at night
• O bebê chorou durante a noite = The baby cried during the night

So durante a noite fits well because it highlights what happened over the course of the night.

Because Portuguese commonly uses the definite article with many time expressions.

So a noite here means the night as a time period.

Other common examples:

• durante o dia = during the day
• durante a semana = during the week
• durante o verão = during the summer

Using the article here is natural and standard.

Yes. Reclamar is often used in a few common patterns:

• reclamar de + noun = to complain about something
• reclamar que + clause = to complain that ...
• reclamar porque + clause = to complain because ...

Examples:

• Ela reclamou do barulho = She complained about the noise
• Ela reclamou que estava cansada = She complained that she was tired
• Ela foi reclamar porque ninguém dormiu = She went to complain because nobody slept

So in your sentence, porque introduces the reason for the complaint.

A helpful approximation is vee-ZEEN-ya.

The most important part for English speakers is nh, which sounds like the ny in canyon.

So:

• vi
• zi
• nha

Stress falls on zi: vi-ZI-nha.

That nh sound is very common in Portuguese, as in:

• minha
• vinho
• senhorinha