Ili elektas komercan programon.

In Esperanto, all present-tense verbs end in -as. So elektas means choose / are choosing / do choose, depending on context.

The verb here is based on the root elekt- = choose.

• elektas = chooses / choose
• elektis = chose
• elektos = will choose
• elekti = to choose

So Ili elektas... means They choose... or They are choosing...

Yes, ili is the Esperanto pronoun for they. It can refer to any plural group of people, animals, or things, depending on context.

Examples:

• Ili venas. = They are coming.
• Ili laboras. = They work.
• Ili estas novaj. = They are new.

Esperanto does not mark gender in ili, so it can mean they for men, women, mixed groups, or non-human things.

Because komercan is describing a direct object, and adjectives in Esperanto must match the noun they describe.

Here, programon is the direct object, and it has the ending -n. So the adjective must also take -n:

• komerca programo = a commercial program
• komercan programon = a commercial program (as the object)

This is called agreement. In Esperanto, adjectives match nouns in:

• number: singular/plural
• case: especially the accusative -n

So:

• singular noun: programo
• singular adjective: komerca
• accusative noun: programon
• accusative adjective: komercan

The -n marks the direct object in Esperanto. The direct object is the thing that receives the action of the verb.

In this sentence:

• Ili = they
• elektas = choose
• programon = program

They are choosing the program, so programon gets the accusative ending -n.

Compare:

• La programo funkcias. = The program works.
  Here programo is the subject, so no -n.
• Ili elektas la programon. = They choose the program.
  Here programon is the object, so it takes -n.

Because adjectives must agree with the nouns they describe.

Since programon is accusative, the adjective describing it must also be accusative:

• programon = program + object marker
• komercan = commercial + matching object marker

You can think of it as a pair:

• komerca programo = a commercial program
• komercan programon = a commercial program as the object

This matching is a very regular feature of Esperanto.

Esperanto has la for the, but it has no indefinite article for a/an.

So:

• programo can mean a program or just program
• la programo means the program

That means Ili elektas komercan programon could be translated as They choose a commercial program unless context makes it definite.

If you wanted to say They choose the commercial program, you would say:

• Ili elektas la komercan programon.

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

The normal order here is:

• Ili elektas komercan programon.

But you could also say:

• Komercan programon ili elektas.

That still means the same thing, because -n shows that programon is the object.

Even so, the most natural basic order is usually subject–verb–object, especially for learners.

Yes, programo is a very similar word and can mean program in several senses, including a software program, a schedule, or a planned course of action, depending on context.

In a sentence like this, komerca programo often sounds like commercial software or a business/commercial program, but the exact meaning depends on the context you were given.

So the grammar is clear, even if the exact nuance of programo depends on the situation.

A simple pronunciation guide is:

• Ili = EE-lee
• elektas = eh-LEK-tahs
• komercan = ko-MER-tsahn
• programon = pro-GRA-mon

A few useful pronunciation notes:

• Esperanto stress is almost always on the second-to-last syllable:
  • i-li
  • e-LEK-tas
  • ko-MER-can
  • pro-GRA-mon
• c is pronounced like ts
• each vowel is pronounced clearly

So komercan has ts, not an English k or s sound alone.

Yes. Esperanto does not have separate simple and progressive present forms the way English does.

So elektas can mean:

• choose
• are choosing
• sometimes do choose, depending on emphasis

The exact English translation depends on context. Esperanto uses the same present-tense ending -as for all of these.

The base dictionary forms are:

• komerca = commercial
• programo = program

In the sentence, they change because of grammar:

• komerca → komercan
• programo → programon

So if you are looking words up, use the forms without the grammatical ending -n.

Not as written. This sentence is singular:

• komercan programon = a commercial program

If it were plural, both the noun and adjective would take -j, and if it were also the object, they would still take -n:

• komercaj programoj = commercial programs
• komercajn programojn = commercial programs (as the object)

So Ili elektas komercajn programojn would mean They choose commercial programs.