Ambaŭ artistoj partoprenos en la koncerto.

Ambaŭ means both.

In this sentence, Ambaŭ artistoj means both artists.

A few useful points:

• ambaŭ already implies two
• it often appears before a plural noun: ambaŭ artistoj
• it can also stand alone: Ambaŭ partoprenos = Both will participate

Unlike English, you do not need a separate word like the unless the context requires it.

The ending -j marks the plural in Esperanto.

So:

• artisto = artist
• artistoj = artists

Because ambaŭ refers to two people, the noun must be plural: ambaŭ artistoj.

Partoprenos means will participate or will take part.

It can be broken down like this:

• parto = part
• preni = to take
• partopreni = to take part, to participate
• -os = future tense

So:

• partopreni = to participate
• partoprenos = will participate

In Esperanto, verbs use fixed endings for tense. The future tense always ends in -os.

Examples:

• partoprenas = participates / is participating
• partoprenis = participated
• partoprenos = will participate

So partoprenos tells you the action happens in the future.

Because Esperanto usually expresses tense directly in the verb ending.

English uses a helper word:

• will participate

Esperanto builds futurity into the verb itself:

• partoprenos

This is very common in Esperanto:

• mi iros = I will go
• ili venos = they will come

Yes, en usually means in.

Here, en la koncerto literally means something like in the concert, but in natural English the meaning is usually in the concert or at the concert, depending on context.

With partopreni, Esperanto commonly uses en to show the event being participated in:

• partopreni en kunveno = participate in a meeting
• partopreni en konkurso = participate in a competition

So partoprenos en la koncerto is the normal way to say will participate in the concert.

La is the definite article, meaning the.

So:

• koncerto = concert
• la koncerto = the concert

It suggests that the concert is a specific one already known from context.

The accusative ending -n is mainly used for a direct object.

In this sentence:

• Ambaŭ artistoj is the subject
• partoprenos is the verb
• en la koncerto is a prepositional phrase

Because koncerto comes after the preposition en, it does not take -n here.

So:

• artistoj has -j for plural
• koncerto has no -n because it is not a direct object

Sometimes you may see ambaŭ la ... in certain contexts, but Ambaŭ artistoj is a very natural and common way to say both artists.

For a learner, Ambaŭ artistoj is the safest and simplest choice here.

Not exactly.

• partopreni = to participate, to take part
• ĉeesti = to be present, to attend

So if the artists are performing or actively involved, partopreni makes sense.

If you only mean they will be there as attendees, ĉeesti might be better.

For example:

• Ambaŭ artistoj partoprenos en la koncerto = Both artists will take part in the concert
• Ambaŭ artistoj ĉeestos la koncerton = Both artists will attend the concert

Esperanto word order is fairly flexible, but this sentence uses a very normal order:

• Ambaŭ artistoj = subject
• partoprenos = verb
• en la koncerto = prepositional phrase

This is clear and natural. Other orders may be possible for emphasis, but learners should usually stick with this standard pattern.

It is pronounced approximately AM-bow, with ow like in English cow, though Esperanto pronunciation is more regular than English.

A rough breakdown:

• am as in father
  • m
• baŭ has the diphthong aŭ, which sounds like ow

So ambaŭ is roughly AM-bow.

A rough English-friendly pronunciation is:

am-BOW ar-TEE-stoy par-to-preh-NOS en la kon-TSER-to

A few details:

• artistoj ends with -oy because oj sounds like oy
• partoprenos has stress on the second-to-last syllable: -pre-
• koncerto has ts for c
• Esperanto stress is usually on the second-to-last syllable

So the stressed syllables are:

• amBAŬ
• arTIStoj
• partoPREnos
• konCERto