Duas páginas do trabalho ficaram por anexar ao relatório final.

Here ficaram does not mean simply stayed in the physical sense.

In this structure, ficar means something like:

• to remain
• to be left
• to end up

So ficaram por anexar means remained to be attached or were left unattached.

This is a very common use of ficar in Portuguese when talking about something that was not completed.

The structure ficar por + infinitive is very important in Portuguese. It means that something has not been done yet or was left still to be done.

So:

• ficou por fazer = it was left undone / it remained to be done
• ficaram por anexar = they were left to attach / they remained unattached

In your sentence, it suggests that the pages should have been attached, but that did not happen.

It is not just describing an action; it highlights incompletion.

Because after por, Portuguese normally uses the infinitive.

So the pattern is:

• ficar por fazer
• ficar por dizer
• ficar por resolver
• ficar por anexar

Not:

• ficar por feitas
• ficar por ditas
• ficar por resolvidas
• ficar por anexadas

So por anexar is the normal fixed structure.

Because the subject is Duas páginas.

Since páginas is:

• feminine
• plural

the verb must agree in number with it:

• Uma página ficou...
• Duas páginas ficaram...

The verb does not agree with trabalho or relatório. It agrees with the main subject, which is duas páginas.

Do is a contraction of:

• de + o = do

So páginas do trabalho literally means pages of the work / paper / assignment.

This phrase tells you which pages we are talking about: the pages belonging to that work/document.

Examples:

• a capa do livro = the cover of the book
• o fim do filme = the end of the film
• duas páginas do trabalho = two pages of the paper/assignment

Ao is a contraction of:

• a + o = ao

Here anexar algo a algo means to attach something to something.

So:

• anexar as páginas ao relatório final = attach the pages to the final report

Because relatório is masculine singular and takes the article o, the combination becomes ao.

Similar contractions:

• a + a = à
• a + os = aos
• a + as = às

Yes, but it would mean something a bit different.

Compare:

• Duas páginas do trabalho ficaram por anexar ao relatório final. = Two pages were left unattached / remained to be attached.

• Duas páginas do trabalho foram anexadas ao relatório final. = Two pages were attached to the final report.

These are opposites in meaning.

A closer alternative would be:

• Duas páginas do trabalho não foram anexadas ao relatório final. = Two pages were not attached to the final report.

But ficaram por anexar has a special nuance: it emphasizes that the action was left incomplete or was still pending.

So não foram anexadas is a neutral statement of non-completion, while ficaram por anexar sounds more like they ended up being left out.

It is not a straightforward passive with ser, but it has a passive-like meaning.

The pages are not doing the action themselves. Instead, the sentence focuses on their status:

• the pages remained unattached
• the pages were left to be attached

So grammatically it uses ficar por + infinitive, but semantically it feels similar to a passive idea.

That is why English translations often use things like:

• were left unattached
• remained to be attached

This is a very natural noun phrase in Portuguese:

• duas = quantity
• páginas = noun
• do trabalho = specification

So it works like:

• two pages of the paper
• three chapters of the book
• some parts of the project

You could rearrange parts of the sentence for emphasis, but this order is the most neutral and natural.

For example:

• Duas páginas do trabalho ficaram por anexar...
  neutral, standard

You could also say:

• Ficaram por anexar ao relatório final duas páginas do trabalho.

This is grammatical, but less neutral and more marked in style.

It depends on context.

In a sentence like this, trabalho often means:

• assignment
• paper
• project
• piece of written work

It usually does not mean job here.

Because the sentence talks about pages and a final report, the most natural reading is something like an academic or professional document.

So trabalho is a broad word, and context decides the best English equivalent.

Yes, anexar is common, especially in formal, administrative, academic, or office contexts.

It is often used for:

• documents
• files
• attachments
• paperwork

For example:

• anexar um ficheiro = attach a file
• anexar um documento = attach a document

In less formal speech, people might also use juntar in some contexts, depending on what exactly is being attached.

But in this sentence, anexar sounds very natural because the context is formal and document-related.