Post la leciono niaj notoj estis legitaj de la instruistino.

Post la leciono means after the lesson.

• post = after
• la leciono = the lesson

This phrase sets the time for the whole sentence. Esperanto often puts time expressions near the beginning, just like English can do with After the lesson, ...

Also, leciono does not take -n here. After a preposition like post, nouns normally do not take the accusative ending unless there is a special reason.

Because adjectives and possessive words in Esperanto agree with the noun they describe.

• notoj is plural because of -j
• so niaj must also be plural

That is why we get:

• nia noto = our note
• niaj notoj = our notes

In Esperanto, possessives like mia, via, nia behave like adjectives, so they match the noun in number and case.

Notoj is the plural of noto.

Here it means notes, usually written notes, such as notes from a lesson.

So:

• noto = a note
• notoj = notes

This is the Esperanto passive.

It is made with:

• a form of esti = to be
• plus a passive participle

Here:

• estis = was / were
• legitaj = read

So estis legitaj means were read.

This is similar to English:

• The notes were read

Esperanto often forms the passive this way, rather than using a single verb form.

Because legitaj agrees with notoj, which is plural.

• notoj = notes
• legitaj = read (plural)

The participle acts like an adjective in this structure, so it must match the subject:

• la noto estis legita = the note was read
• la notoj estis legitaj = the notes were read

Because in this passive sentence, notoj is the subject, not the direct object.

Compare:

• Active: La instruistino legis niajn notojn.
  Here niajn notojn is the direct object, so it takes -n.

• Passive: Niaj notoj estis legitaj de la instruistino.
  Here niaj notoj becomes the subject, so there is no -n.

This is one of the biggest changes when a sentence goes from active to passive.

De la instruistino means by the teacher.

In a passive sentence, Esperanto commonly uses de to show the agent, meaning the person who did the action.

So:

• Niaj notoj estis legitaj de la instruistino.
• Our notes were read by the teacher.

This is the normal way to express the doer in a passive sentence.

Because -in- is the feminine suffix in Esperanto.

• instruisto = teacher
• instruistino = female teacher

So this sentence specifically says that the teacher is female.

The active version would be:

Post la leciono la instruistino legis niajn notojn.

That means:

• the teacher read our notes after the lesson

Notice the changes:

• la instruistino becomes the subject
• niajn notojn becomes the object, so it takes -n
• estis legitaj becomes the active verb legis

Yes. Esperanto word order is fairly flexible.

For example, you could also say:

• Niaj notoj estis legitaj de la instruistino post la leciono.

This means basically the same thing.

The original version puts Post la leciono first to emphasize the time. That is very natural.

Because the sentence describes something that had already happened: the notes were read.

The verb legi means to read. Its passive participles include:

• legata = being read
• legita = read, having been read
• legota = going to be read

Here the sentence uses legita because the action is completed. Since notoj is plural, it becomes legitaj.

So:

• estis legitaj = were read

Yes, in this sentence it works the same way.

It tells us when the main action happened. It does not describe movement or direction; it simply places the action in time.

So the structure is very straightforward:

• Post la leciono = after the lesson
• niaj notoj estis legitaj de la instruistino = our notes were read by the teacher