Ya he terminado la reseña, pero todavía no he revisado la bibliografía.

In Spain Spanish, the present perfect (he terminado, he revisado) is very commonly used for actions connected to the present, especially when talking about something that has happened today, recently, or in a time period that still feels current.

So this sentence suggests:

• I have already finished the review
• but I still haven’t checked the bibliography

That feels relevant right now.

In many parts of Latin America, speakers might more often use the simple past here:

• Ya terminé la reseña, pero todavía no revisé la bibliografía.

Both are grammatical, but he terminado / he revisado is especially natural in Spain.

The Spanish present perfect is formed with:

• the present tense of haber
• plus a past participle

Here:

• he terminado = he
  • terminado
• he revisado = he
  • revisado

The forms of haber are:

• he
• has
• ha
• hemos
• habéis
• han

Examples:

• He comido = I have eaten
• Has llegado = you have arrived
• Han salido = they have left

For regular verbs:

• -ar verbs → -ado
  
  • terminar → terminado
  • revisar → revisado
• -er / -ir verbs → -ido
  
  • comer → comido
  • vivir → vivido

Ya here means already.

So:

• Ya he terminado la reseña = I have already finished the review

It often gives the idea that something is completed sooner than expected, by now, or simply at this point.

Common examples:

• Ya he comido. = I’ve already eaten.
• Ya lo sé. = I already know.
• Ya viene. = He/She is coming now / already on the way.

The exact English translation of ya depends on context, but already is the best fit in this sentence.

Todavía no means not yet.

So:

• todavía no he revisado la bibliografía = I haven’t checked the bibliography yet

Why both words?

• todavía = still / yet
• no = not

Together, they create the idea of something has not happened up to now, but it may happen later.

Compare:

• No he revisado la bibliografía. = I haven’t checked the bibliography.
• Todavía no he revisado la bibliografía. = I haven’t checked the bibliography yet.

The second one more clearly suggests it remains to be done.

In Spanish, no normally goes directly before the conjugated verb.

Here, the conjugated verb is he (from haber), so:

• no he revisado

Not:

• he no revisado ❌

This is the normal pattern:

• No tengo tiempo.
• No he comido.
• No puedo ir.

When there is a compound tense, the negative still goes before the auxiliary:

• No he terminado
• No había visto
• No habría dicho

Spanish often uses the definite article more regularly than English does. In this sentence, la reseña and la bibliografía refer to specific things that both speaker and listener can identify, probably as parts of a particular assignment, article, or project.

So:

• la reseña = the review
• la bibliografía = the bibliography

Even when English might sometimes leave the article out in certain contexts, Spanish often keeps it.

Also, both nouns are feminine singular, so the article is la.

Yes, both are feminine singular nouns:

• la reseña
• la bibliografía

Why?

• Nouns ending in -a are often feminine, though not always.
• bibliografía is clearly feminine because it refers to -grafía words, which are usually feminine.
• reseña is also feminine by standard usage.

You usually learn noun gender together with the article:

• la reseña
• la bibliografía

That is the safest habit.

Because in the present perfect, the past participle does not agree with the object.

So we say:

• He terminado la reseña
• He revisado la bibliografía

not:

• He terminada la reseña ❌
• He revisada la bibliografía ❌

When the past participle is used with haber, it stays in its standard form:

• -ado
• -ido

Agreement happens in other structures, for example with adjectives or sometimes with estar used adjectivally:

• La reseña está terminada. = The review is finished.
• La bibliografía está revisada. = The bibliography is checked/reviewed.

There, terminada and revisada do agree with the feminine noun.

Not usually, unless you mean something different.

Reseña usually means:

• a review
• a write-up
• a short critical summary, for example of a book, film, or article

Revisión usually means:

• revision
• checking
• inspection
• review in the sense of examining something carefully

So in this sentence:

• la reseña = the written review itself
• he revisado la bibliografía = I have checked/reviewed the bibliography

If you said he terminado la revisión, that would usually mean I have finished the revision/checking, not I have finished writing the review.

It can be tricky because it is a false friend.

In Spanish, revisar often means:

• to check
• to inspect
• to go over
• to review

In this sentence, he revisado la bibliografía most naturally means:

• I have checked/reviewed the bibliography

In British English, revise can mean study again, especially for an exam. Spanish revisar usually does not mean that.

Examples:

• Voy a revisar el documento. = I’m going to check/review the document.
• El mecánico revisó el coche. = The mechanic checked the car.

So be careful: Spanish revisar is often closer to check or go over than to English revise.

Yes, Spanish word order is somewhat flexible, although some versions sound more natural than others depending on emphasis.

The original:

• Ya he terminado la reseña
  is very natural and neutral.

You could also say:

• He terminado ya la reseña
• La reseña ya la he terminado
  This adds emphasis to la reseña.

For the second part:

• Todavía no he revisado la bibliografía
  is the standard and most natural order.

So yes, word order can change, but the original sentence is a very natural default.

Here pero simply means but and introduces a contrast:

• one task is finished: Ya he terminado la reseña
• another task is not finished: todavía no he revisado la bibliografía

So the contrast is:

• completed task vs.
• pending task

That is exactly the kind of situation where pero is used.

The vocabulary would generally be understood, but there are two things to note:

1. Tense choice

   • In Spain, Ya he terminado... is very natural.
   • In much of Latin America, many speakers would more often say:
   • Ya terminé la reseña, pero todavía no revisé la bibliografía.

2. Vocabulary nuance

   • reseña is widely understood, but depending on context, some speakers might prefer another word such as comentario, crítica, or something more specific.
   • bibliografía is standard everywhere.

So the sentence is correct and understandable across the Spanish-speaking world, but the present perfect especially gives it a Spain-Spanish feel.