Post du horoj ni bezonas pli longan paŭzon, ĉar la leciono estas longa.

Because post is a preposition, and in Esperanto prepositions normally take the basic form of the noun phrase, not the accusative.

So:

• post du horoj = after two hours
• dum du horoj = for two hours
• antaŭ la leciono = before the lesson

The -n ending is not used here just because a time expression is involved. It is the preposition post that controls the phrase.

A related pattern you may also see is:

• du horojn poste = two hours later

There, du horojn is an adverbial time expression, so the accusative can appear.

Because paŭzon is the direct object of bezonas.

The sentence says:

• ni bezonas pli longan paŭzon
• we need a longer break

The thing being needed is paŭzo, so it takes the accusative ending:

• paŭzo = break
• paŭzon = break as a direct object

This is one of the most important uses of -n in Esperanto.

Because longan is describing paŭzon, and adjectives must agree with the nouns they describe.

Here:

• paŭzon is singular and accusative
• so the adjective must also be singular and accusative: longan

That gives:

• pli longan paŭzon = a longer break

Compare:

• longa paŭzo = a long break
• longan paŭzon = a long break as an object
• pli longa paŭzo = a longer break
• pli longan paŭzon = a longer break as an object

Because longa here is a predicate adjective, not a direct object.

In:

• la leciono estas longa

longa describes the subject la leciono after the verb estas. It is not receiving the action of the verb, so it does not take -n.

So:

• Mi bezonas longan paŭzon. → longan gets -n because it describes the object.
• La paŭzo estas longa. → longa has no -n because it is part of the predicate.

Pli means more, and with an adjective it forms the comparative:

• longa = long
• pli longa = longer

So:

• pli longan paŭzon = a longer break

Esperanto forms comparisons very simply:

• granda = big
• pli granda = bigger
• la plej granda = the biggest

There is no need to change the adjective itself the way English changes long to longer.

Esperanto has only one article: la, which means the. There is no separate word for a/an.

So:

• la leciono = the lesson
• paŭzo can mean a break or just break, depending on context

In this sentence:

• la leciono refers to a specific lesson
• pli longan paŭzon means a longer break

So the absence of an article before paŭzon is normal. Esperanto does not use an indefinite article.

Ĉar means because.

It introduces the reason:

• ni bezonas pli longan paŭzon = we need a longer break
• ĉar la leciono estas longa = because the lesson is long

So the whole sentence means:

• We need a longer break, because the lesson is long.

You do not add another word like that after ĉar.
So ĉar by itself is enough.

Yes, Esperanto word order is fairly flexible, as long as the grammar markings remain clear.

The original sentence is:

• Post du horoj ni bezonas pli longan paŭzon, ĉar la leciono estas longa.

You could also say:

• Ni bezonas pli longan paŭzon post du horoj, ĉar la leciono estas longa.

That means essentially the same thing.

The -n ending helps show what the object is, so Esperanto does not rely on word order as heavily as English does. Still, some word orders sound more natural than others depending on emphasis.

Bezonas means need.

So:

• ni bezonas pli longan paŭzon = we need a longer break

It is not exactly the same as must.

Compare:

• Ni bezonas paŭzon. = We need a break.
• Ni devas paŭzi. = We must pause / We have to take a break.

Bezonas focuses on necessity from a practical point of view.
Devas sounds more like obligation or requirement.

In normal Esperanto, adjectives stay adjectives, and esti is used just like to be in English.

So:

• la leciono estas longa = the lesson is long

Esperanto does allow some flexibility with word classes in certain contexts, but for a learner, the standard and safest pattern is:

• noun + estas
  • adjective

Examples:

• La libro estas interesa. = The book is interesting.
• La vojo estas mallonga. = The road is short.

Ni means we.

It is the subject of bezonas:

• ni bezonas = we need

Esperanto subject pronouns are straightforward:

• mi = I
• vi = you
• li = he
• ŝi = she
• ĝi = it
• ni = we
• ili = they

Since the verb ending does not change for person, the pronoun is important:

• mi bezonas
• ni bezonas
• ili bezonas

The verb form bezonas stays the same.

Yes. Du horoj literally means two hours.

After numbers, nouns are usually plural if the number is greater than one:

• unu horo = one hour
• du horoj = two hours
• tri lecionoj = three lessons

The adjective agreement rules still apply if there is an adjective:

• du longaj lecionoj = two long lessons

In this sentence, du horoj is simply a time expression after the preposition post.

Paŭzo is pronounced approximately like POW-zoh.

A few helpful points:

• aŭ sounds like the ow in cow
• z is always like English z
• o is a pure vowel, like o in many European languages, not a diphthong

So:

• paŭzo ≈ POW-zoh

This word is related in meaning to English pause, so it may feel familiar.

In this sentence, post du horoj means after two hours.

For English speakers, this can be tricky, because English sometimes uses time phrases in overlapping ways. Esperanto is more direct here:

• post du horoj = after two hours
• post du horoj ni bezonas paŭzon = after two hours, we need a break

If you want to say in two hours in the sense of two hours from now, Esperanto often uses context or other phrasing, such as:

• post du horoj = after two hours / two hours from now

So the exact English translation can depend on context, but the core meaning of post is still after.

The comma separates the main statement from the reason clause.

Main clause:

• Post du horoj ni bezonas pli longan paŭzon

Reason clause:

• ĉar la leciono estas longa

This is similar to English punctuation in sentences like:

• We need a longer break, because the lesson is long.

In Esperanto, commas are commonly used to separate clauses, especially when a conjunction like ĉar introduces a new clause.