Mia kolegino demandas, ĉu la estro jam legis la lastan paĝon de mia raporto.

The suffix -in- marks female sex, so kolegino means female colleague.

• kolego = colleague
• kolegino = female colleague

In modern Esperanto, kolego is often used as a general word for colleague regardless of sex, but kolegino is used when the speaker specifically wants to show that the colleague is female.

Ĉu introduces a yes/no question, including an indirect yes/no question.

Here it means something like whether.

So after demandas, ĉu tells you that the colleague is asking a question that can be answered with yes or no.

Compare:

• Li demandas, ĉu ŝi venos. = He asks whether she will come.
• Li demandas, kiam ŝi venos. = He asks when she will come.

In the second example, kiam introduces an information question, not a yes/no question.

Because ĉu la estro jam legis... is a subordinate clause.

Esperanto normally separates subordinate clauses with commas more consistently than English often does. So after demandas, the comma is standard:

• Mia kolegino demandas, ĉu...

Because demandi can directly introduce the thing being asked, including a whole clause.

So demandi, ĉu... is a normal pattern:

• Mi demandas, ĉu li venos.
• Ŝi demandas, kie vi loĝas.

You do not need an extra word equivalent to English if or whether beyond ĉu itself.

La shows that this is a specific, identifiable boss: the boss.

Esperanto uses la for something known or clear from context. In this sentence, the speaker and listener presumably know which boss is meant.

Without la, estro would sound more like a boss or some boss, which is probably not the intended meaning here.

Jam means already or by now.

Placed before legis, it modifies the reading action:

• jam legis = has already read / already read

Its position is fairly natural here. Esperanto word order is somewhat flexible, but this placement is the most neutral and common.

Because legis marks the action as completed in the past.

In Esperanto, the past tense often covers what English expresses as either:

• read
  or
• has read

So jam legis is the normal way to say has already read.

This is important: Esperanto does not use English-style tense backshifting in the same way. The verb tense is chosen by the actual time of the action, not just by the tense of demands.

So:

• demandas, ĉu la estro jam legis... = asks whether the boss has already read...

Yes, but usually it does not need to.

You could theoretically use a more explicit form like estas leginta, but that is much less common here and would usually sound heavier than necessary.

In ordinary Esperanto, jam legis is the normal, idiomatic choice.

Because paĝon is the direct object, and its adjective must agree with it.

• paĝo = page
• paĝon = page as a direct object
• lasta paĝo = last page
• lastan paĝon = last page as a direct object

In Esperanto, adjectives agree with nouns in both number and case, so if the noun gets -n, the adjective gets -n too.

Because de is the normal way to show a relationship like of.

So:

• la lasta paĝo de mia raporto = the last page of my report

Esperanto does not use an apostrophe-s like English. Instead, it commonly uses de.

Because sia refers to the subject of its own clause.

In the clause ĉu la estro jam legis la lastan paĝon de mia raporto, the subject is la estro. So:

• sia raporto would mean the boss's own report
• mia raporto means my report

Since the report belongs to the speaker, mia is correct.

This is a very important Esperanto rule: sia is reflexive and points back to the subject of the same clause, not automatically to the main speaker.

Because raporto is not the direct object.

The direct object is paĝon. The phrase de mia raporto is just a de-phrase describing which page it is.

So:

• la lastan paĝon = the direct object
• de mia raporto = a modifier of paĝon

That is why only paĝon gets the object ending.

Usually lasta means last in the sense of final in a sequence.

So la lasta paĝo normally means the final page.

If you want latest in the sense of most recent, Esperanto often uses something like:

• la plej nova
• la plej freŝa
  depending on context

So learners should be careful not to assume that lasta always matches English latest.

Not completely, but this order is the most neutral and natural.

Esperanto allows some flexibility because endings show grammatical roles. Still, this sentence uses a very standard order:

• subject: Mia kolegino
• verb: demandas
• subordinate clause: ĉu la estro jam legis...

Within the ĉu-clause, putting ĉu first is normal, and jam before the verb is also very natural.

So while other orders may be possible, this one is the best model for learners.