La donacon alportinta gasto sidas ĉe la tablo.

Alportinta is an active past participle.

It breaks down like this:

• al- = to, toward
• port- = carry, bring
• -int- = active past participle, meaning having done something
• -a = adjective ending

So alportinta means having brought or who brought.

In this sentence, la donacon alportinta gasto literally means something like the gift-bringing guest or more naturally the guest who brought the gift.

Because donacon is the direct object of alportinta.

The verb idea inside alportinta is alporti = to bring.
What was brought? La donaco. Since it is the direct object, it takes the accusative ending -n:

• la donaco = the gift
• la donacon = the gift, as the object

So:

• la donacon alportinta gasto = the guest who brought the gift

Even though alportinta is a participle, it still keeps the same object relationship that the verb alporti would have.

Because alportinta agrees with gasto, not with donacon.

In Esperanto, participles used like adjectives behave like adjectives. That means they match the noun they describe in:

• number
• case

Here, gasto is singular and not accusative, so the participle is also singular and not accusative:

• alportinta gasto

If the whole noun phrase were accusative, then both would change:

• Mi vidas la donacon alportintan gaston.
  = I see the guest who brought the gift.

So donacon gets -n because it is the object of alporti, while alportinta follows gasto.

Because the whole phrase la donacon alportinta describes gasto.

Esperanto often puts descriptive adjectives and participial modifiers before the noun:

• bela domo = beautiful house
• veninta amiko = a friend who came
• la donacon alportinta gasto = the guest who brought the gift

This is a compact way of saying the same thing as a relative clause:

• La gasto, kiu alportis la donacon, sidas ĉe la tablo.

Both are correct. The participial version is just more condensed.

Yes. That is completely correct and means the same thing.

Compare:

• La donacon alportinta gasto sidas ĉe la tablo.
• La gasto, kiu alportis la donacon, sidas ĉe la tablo.

The first is more compact and uses a participle.
The second uses a relative clause with kiu alportis = who brought.

For learners, the relative clause version may feel more familiar at first. The participial version is very common and elegant, but it can take some getting used to.

Alportis is a finite verb: brought.
Alportinta is a participle: having brought or who brought.

Compare:

• La gasto alportis la donacon.
  = The guest brought the gift.

• La donacon alportinta gasto
  = the guest who brought the gift

So alportis can be the main verb of a sentence, while alportinta cannot. It functions like an adjective describing a noun.

Yes. Usually that is the idea.

The -int- participle shows that the action of bringing is earlier than the action or situation of the main verb.

So in:

• La donacon alportinta gasto sidas ĉe la tablo.

the guest is now sitting, and the bringing happened before that.

That is why -int- is called the active past participle.

A useful contrast:

• alportanta = bringing, in the process of bringing
• alportinta = having brought, who brought
• alportonta = about to bring, going to bring

Because all three nouns are being treated as definite: the gift, the guest, the table.

Esperanto has only one article, la, and it does not change for case or number.

So:

• la donacon = the gift
• la gasto = the guest
• la tablo = the table

Whether English would say a or the depends on context, but Esperanto uses la when the speaker assumes the listener can identify the thing.

Ĉe la tablo means at the table or by the table.

It usually means being near the table, in the position of sitting or standing there.

• sidas ĉe la tablo = is sitting at the table

Sur la tablo means on the table, physically on top of it.

So:

• La gasto sidas ĉe la tablo.
  = The guest is sitting at the table.

• La gasto sidas sur la tablo.
  = The guest is sitting on the table.

Those mean very different things.

No, Esperanto word order is fairly flexible, because endings show grammatical roles.

This sentence could be rearranged for style or emphasis, for example:

• La donacon alportinta gasto sidas ĉe la tablo.
• Ĉe la tablo sidas la donacon alportinta gasto.

Both are grammatical.

However, the original order is very natural and clear. For learners, it is usually best to keep a straightforward word order unless you have a reason to emphasize something.

Because the endings show the roles.

• donacon has -n, so it is the direct object
• gasto has no -n, so it is not the object here
• alportinta agrees with gasto, so it describes the guest

That means the guest is the one doing the bringing, and the gift is what was brought.

This is one of the strengths of Esperanto: the grammar endings make relationships clear even when the word order is more flexible.

Yes. Since participles used as adjectives agree with the noun, they change for number and case.

Examples:

• la donacon alportinta gasto = the guest who brought the gift
• la donacon alportintaj gastoj = the guests who brought the gift

If accusative were needed:

• Mi vidas la donacon alportintajn gastojn.
  = I see the guests who brought the gift.

So the participle behaves like an adjective and must match the noun it describes.

It is natural and correct Esperanto.

The participial style can feel a bit more formal or compressed than a kiu clause, especially to beginners, but it is definitely normal Esperanto. You will see this kind of structure often in writing and also in careful speech.

A learner may initially prefer:

• La gasto, kiu alportis la donacon, sidas ĉe la tablo.

But the participial version is very useful and worth learning:

• La donacon alportinta gasto sidas ĉe la tablo.