Llevo escritas tres páginas del informe, pero todavía no he revisado el último párrafo.

This is the pattern llevar + past participle + quantity/object, which is used to show how much progress has been made up to now.

So:

• Llevo escritas tres páginas = I have three pages written so far
• It focuses on the current result/progress, not just the fact that the action happened

This is very common in Spanish:

• Llevo leídos dos capítulos = I’ve read two chapters so far
• Llevamos hechas muchas cosas = We’ve got many things done so far

It often sounds more progress-oriented than a simple perfect tense.

Because in this structure, the past participle agrees with the thing that has been done.

Here, the thing written is:

• tres páginas → feminine plural

So the participle must also be feminine plural:

• escritas

Compare:

• Llevo escrito un informe → informe is masculine singular
• Llevo escritas tres páginas → páginas is feminine plural
• Llevo escritos dos correos → correos is masculine plural

This agreement happens with llevar + participle in this type of sentence.

Because he revisado uses haber + past participle, and with haber, the participle does not agree with the object.

So you say:

• he revisado el último párrafo
• he revisado las últimas páginas

In both cases, it stays revisado, not revisadas.

That is a key difference:

• llevar + participle → agreement usually happens
• haber + participle → no agreement

Both can mean that three pages have been written, but the nuance is different.

• He escrito tres páginas = I have written three pages
  • simply states the completed action
• Llevo escritas tres páginas = I’ve got three pages written so far
  • emphasizes progress up to this point
  • suggests the task may still be ongoing

So in this sentence, llevo escritas fits well because the speaker is talking about the current state of work on the report.

Del informe means of the report and specifies what those pages belong to.

• tres páginas = three pages
• tres páginas del informe = three pages of the report

Without del informe, the sentence would still be grammatical, but less specific.

Also, del is just:

• de + el = del

In standard Spanish from Spain, the present perfect (he revisado) is very commonly used for past actions that are still connected to the present moment.

Here, the idea is:

• up to now, I haven’t reviewed the last paragraph

That is why todavía no he revisado sounds very natural in Spain.

In many parts of Latin America, people would often use the preterite instead in similar contexts:

• todavía no revisé el último párrafo

Both are grammatical, but no he revisado is especially typical of Spain.

Todavía no means not yet.

So:

• todavía no he revisado el último párrafo = I haven’t reviewed the last paragraph yet

It shows that the action is expected or intended to happen later, but it has not happened so far.

A very similar word is aún:

• todavía no he revisado...
• aún no he revisado...

Both are correct here.

Spanish often uses the definite article where English might use a possessive or no article at all.

Here, el último párrafo means the last paragraph. It is understood that this is the last paragraph of the report.

Spanish prefers the article because the context already makes it clear which paragraph is meant.

In Spanish, revisar usually means to check, to go over, or to review.

In this sentence, it means something like:

• to review
• to check over

Be careful with the English word revise, because in British English it can mean study again, and in American English it often means edit/change. Spanish revisar does not always match every meaning of English revise.

If you wanted to emphasize correcting the paragraph, you might also use:

• corregir = to correct
• editar = to edit

Yes, but the original order is the most natural and neutral:

• Llevo escritas tres páginas del informe

Spanish allows some flexibility, but changing the order may sound more marked or literary. For example:

• Tres páginas del informe llevo escritas

This is possible, but it puts special emphasis on tres páginas del informe.

For most learners, the standard order is the safest choice.

Yes, you could, but the meaning is slightly different.

• Tengo escritas tres páginas del informe = I have three pages of the report written
  • focuses more on the current state/result
• Llevo escritas tres páginas del informe = I’ve written three pages of the report so far
  • focuses more on progress up to now

Both are correct, but llevo escritas fits especially well when talking about work in progress.

Because pero joins two independent parts of the sentence:

• Llevo escritas tres páginas del informe
• todavía no he revisado el último párrafo

In Spanish, it is normal to put a comma before pero when it connects two full clauses like this.

So the punctuation here is standard and natural.