La unua paĝo jam estas legita, sed la dua ankoraŭ ne.

Unua means first and dua means second.

In Esperanto, ordinal numbers are made by taking the basic number and adding -a:

• unu = one → unua = first
• du = two → dua = second
• tri = three → tria = third

Because -a is the adjective ending, these words behave like adjectives and describe a noun:

• unua paĝo = first page
• dua paĝo = second page

La is the definite article, meaning the.

So:

• la unua paĝo = the first page
• la dua = the second one/page

In this sentence, we are talking about specific pages, not just any first or second page in general. That is why la is used.

Because the noun paĝo is understood from the earlier part of the sentence, so Esperanto leaves it out to avoid repetition.

Full version:

• La unua paĝo jam estas legita, sed la dua ankoraŭ ne.

Expanded version:

• La unua paĝo jam estas legita, sed la dua paĝo ankoraŭ ne estas legita.

This is very natural. English does the same thing:

• The first page has already been read, but the second one has not yet.

Jam means already.

So:

• jam estas legita = has already been read / is already read

It shows that the action is completed earlier than expected or earlier than some comparison point.

Yes, literally it is close to still not, but in English it is often best translated as not yet.

So:

• ankoraŭ ne = not yet

Examples:

• Mi ankoraŭ ne manĝis. = I haven’t eaten yet.
• Li ankoraŭ ne venis. = He hasn’t come yet.

In your sentence:

• sed la dua ankoraŭ ne = but the second one has not yet

Because estas legita is a passive construction.

• legi = to read
• legita = read, having been read
• estas legita = is read / has been read

The important point is that the sentence is about the page, not about the person doing the reading.

Compare:

• Mi legis la unuan paĝon. = I read the first page.

  • active: the subject is the reader

• La unua paĝo estas legita. = The first page has been read.

  • passive: the subject is the page

So Esperanto uses esti + participle to make the passive.

This is about the meaning of the participle.

• legata = being read, in the process of being read
• legita = read, already read, finished

In this sentence, the idea is that the first page is completed, so legita is the correct form.

Compare:

• La paĝo estas legata. = The page is being read.
• La paĝo estas legita. = The page has been read.

Because it functions like an adjective and agrees with the noun.

In Esperanto, adjectives end in -a:

• bona libro = good book
• legita paĝo = read page

Here, legita describes paĝo, so it takes the adjective ending -a.

If the noun were plural, the adjective would also be plural:

• La unuaj paĝoj estas legitaj. = The first pages have been read.

Because paĝo is the subject of the sentence, not the direct object.

In Esperanto, -n marks the direct object:

• Mi legas la paĝon. = I am reading the page.

But in your sentence, the page is the thing being talked about as the subject:

• La unua paĝo estas legita.

So no accusative -n is needed.

Yes, but it is omitted because it is understood from the first half.

The full idea is:

• sed la dua ankoraŭ ne estas legita

But Esperanto, like English, often leaves out repeated words when they are obvious.

So this is a natural shortened form.

English does the same:

• The first page has already been read, but the second one has not yet.

We do not need to repeat been read.

Grammatically, yes, but in natural English the usual meaning is better expressed as:

• The first page has already been read, but the second has not yet.

Esperanto estas legita can sometimes look like a simple present passive, but in many contexts it refers to a completed result. In this sentence, that is clearly the idea: the first page is finished, the second is not.

Yes. Sed means but and is used to contrast two ideas.

Here the contrast is:

• first page: already read
• second page: not yet read

So:

• La unua paĝo jam estas legita, sed la dua ankoraŭ ne.
• The first page has already been read, but the second has not yet.

The word order is natural, but Esperanto is often more flexible than English.

This order is especially clear:

• La unua paĝo — subject
• jam — already
• estas legita — has been read
• sed — but
• la dua — the second one
• ankoraŭ ne — not yet

You could sometimes move adverbs for emphasis, but the given version is the most straightforward and idiomatic for a learner.