La substrato sorbas akvon rapide.

In Esperanto, -as marks the present tense. So sorbas means absorbs / is absorbing.

The verb here is built like this:

• sorb- = the root, meaning absorb
• -as = present tense

Some related forms are:

• sorbas = absorbs
• sorbis = absorbed
• sorbos = will absorb
• sorbi = to absorb

The -n ending marks the direct object in Esperanto.

In this sentence:

• La substrato = the subject, the thing doing the action
• sorbas = absorbs
• akvon = the thing being absorbed

So akvon has -n because it receives the action of the verb.

This is one of the most important features of Esperanto grammar. English mostly uses word order to show this, but Esperanto often uses the accusative ending -n.

Because rapide is an adverb, and adverbs in Esperanto usually end in -e.

Here, rapide describes how the absorbing happens:

• rapida = quick, fast (an adjective)
• rapide = quickly, fast (an adverb)

Compare:

• rapida substrato = a quick substrate (adjective describing a noun)
• sorbas rapide = absorbs quickly (adverb describing a verb)

So rapide is correct because it modifies sorbas.

La is the definite article, meaning the.

So:

• la substrato = the substrate

Esperanto has only one article: la. It does not change for gender, number, or case.

Also, Esperanto has no indefinite article. So:

• substrato can mean a substrate or just substrate
• la substrato means the substrate

Because Esperanto does not require the definite article unless you mean something specific.

So:

• akvon = water
• la akvon = the water

In many contexts, especially with mass nouns like water, leaving out la is completely natural if you are talking about water in a general sense.

So La substrato sorbas akvon rapide sounds like The substrate absorbs water quickly, not necessarily the water.

Yes. Esperanto word order is fairly flexible, because endings show the grammatical roles.

This sentence could also appear as:

• La substrato rapide sorbas akvon.
• Akvon la substrato sorbas rapide.
• Rapide la substrato sorbas akvon.

All of these are understandable because akvon still has the -n ending, so it is still the object.

That said, the most neutral order is usually:

• subject + verb + object + adverb

So La substrato sorbas akvon rapide is a normal, straightforward sentence.

It is a normal Esperanto word, but it is clearly an international/technical word.

Esperanto often uses roots that are recognizable from European scientific vocabulary. Substrato is one of those. It works like any regular Esperanto noun:

• substrato = substrate
• substratoj = substrates
• la substrato = the substrate
• la substraton = the substrate (as direct object)

So even though it may sound technical, its grammar is completely regular.

There are two clues:

1. It does not have the -n ending.
2. It is the thing doing the action of sorbas.

In Esperanto, the direct object usually gets -n, but the subject does not.

So here:

• La substrato = subject
• akvon = object

That tells you that the substrate is doing the absorbing.

Yes. Adverbs are often fairly movable in Esperanto.

All of these are natural:

• La substrato sorbas akvon rapide.
• La substrato rapide sorbas akvon.
• Rapide la substrato sorbas akvon.

The meaning stays basically the same, though placement can slightly change emphasis.

• rapide at the end sounds very neutral
• rapide before the verb may emphasize the speed a bit more

Esperanto pronunciation is very regular. sorbas is pronounced roughly like:

• SOR-bahs

A simple breakdown:

• s = like English s
• o = a pure o sound
• r = a rolled or tapped r
• b = like English b
• a = ah
• s = s

The stress in Esperanto is always on the second-to-last syllable, so here it falls on sor:

• SOR-bas

Yes, depending on context, but sorbi is the more direct word for to absorb.

• sorbi = to absorb, soak up
• absorbi also exists and may sound more international or technical in some contexts

In many cases both are understandable, but sorbas is a very natural Esperanto choice here.