Ŝi prezentas la planton al la grupo.

The -n marks the direct object of the verb: the thing being presented.

• la planto = the plant
• la planton = the plant as the object of the action

In this sentence, she is doing the action of presenting, and the plant is what is being presented, so Esperanto uses -n.

Al means to.

It shows the recipient or direction toward someone/something.

So:

• la planton = the thing being presented
• al la grupo = to the group

A helpful way to see the structure is:

• Ŝi prezentas = she presents
• la planton = the plant
• al la grupo = to the group

In Esperanto, verbs do not change depending on the subject.

So:

• mi prezentas = I present
• vi prezentas = you present
• ŝi prezentas = she presents
• ili prezentas = they present

The ending -as always marks the present tense, regardless of who is doing the action.

-as is the Esperanto ending for the present tense.

So prezentas means presents / is presenting.

Esperanto does not usually make a special distinction between:

• she presents
• she is presenting

Both can be expressed with ŝi prezentas, and context tells you which is more natural.

La is the Esperanto word for the.

So:

• la planton = the plant
• la grupo = the group

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

Also, Esperanto has no word for a/an. If you want an indefinite idea, you often simply leave out the article.

For example:

• Ŝi prezentas planton al grupo would sound more like She presents a plant to a group.

Yes, sometimes prezenti can mean to introduce, depending on context.

For example:

• Ŝi prezentas sian amikon al la grupo. = She introduces her friend to the group.

With planton, the meaning is more likely presents, shows, or introduces/presents for attention rather than introducing a person socially.

So the exact English translation depends on context, even though the Esperanto verb stays the same.

Yes, Esperanto word order is fairly flexible, but this sentence uses the most neutral order:

subject + verb + object + prepositional phrase

• Ŝi = subject
• prezentas = verb
• la planton = direct object
• al la grupo = recipient phrase

Because la planton has the -n ending, its role is clear even if the order changes. But the usual and easiest order for learners is the one shown here.

Because grupo is not the direct object.

The direct object is la planton.
La grupo is part of the prepositional phrase al la grupo.

In Esperanto, a noun after a preposition like al normally does not take -n just because it follows the preposition.

So:

• la planton = object of the verb
• al la grupo = prepositional phrase meaning to the group

Ŝi is pronounced roughly like shee.

• ŝ sounds like English sh
• i sounds like ee

So ŝi is very close to English she, except the Esperanto i is always a clear ee sound.

Usually, Esperanto keeps the subject pronoun.

That is because the verb form prezentas does not tell you whether the subject is I, you, she, they, and so on. The pronoun helps make the sentence clear.

So Ŝi prezentas... is the normal full sentence.

In special contexts, the pronoun can sometimes be omitted if the subject is already obvious, but that is not the basic pattern learners should rely on.

The dictionary forms are:

• prezenti = to present
• planto = plant

Esperanto words often change by adding standard endings:

• prezenti → prezentas
  (-i infinitive, -as present tense)

• planto → planton
  (-o noun ending, -n object marker)

This is a very common pattern in Esperanto and one of the reasons its grammar is considered regular.