Она исполняет дуэт.

Она means she.

You do not always have to include it in Russian, because the verb ending often already shows who the subject is. Here, исполняет is third person singular, so in context Исполняет дуэт could already mean she is performing a duet.

Still, она is completely normal to use when:

• you are introducing the subject,
• you want to make it clear who is doing the action,
• or you want a little emphasis on she.

Исполняет is the 3rd person singular present tense form of исполнять.

So:

• я исполняю = I perform
• ты исполняешь = you perform
• он / она исполняет = he / she performs

In this sentence, исполняет agrees with она, so the meaning is she performs / she is performing.

Russian present tense often covers both ideas that English separates:

• She performs a duet
• She is performing a duet

The exact English translation depends on context.

Russian does not always force you to choose between:

• a general/habitual meaning, and
• an action happening right now

So Она исполняет дуэт could mean:

• she performs duets, in this situation
• she is performing a duet now
• she performs a duet as part of a program or role

Context tells you which is meant.

Not exactly.

Исполнять means to perform. It is a broader and often more formal verb, especially for music, dance, theater, or other artistic works.

So исполняет дуэт means something like:

• performs a duet
• renders a duet in a musical sense

By contrast, петь means specifically to sing.

So:

• Она поёт = she sings
• Она исполняет дуэт = she performs a duet

If the duet is vocal, both ideas may overlap, but исполнять focuses more on the performance as a piece of music, not just the act of singing.

Дуэт is the direct object of исполняет, so it is in the accusative case.

However, for many masculine inanimate nouns, the accusative singular looks exactly the same as the nominative singular.

So:

• nominative: дуэт
• accusative: дуэт

That is why there is no visible change here.

This is normal for masculine inanimate nouns in Russian.

In Russian, nouns have grammatical gender. Дуэт is a masculine noun.

A good clue is that it ends in a consonant: дуэт. Many Russian nouns ending in a consonant are masculine.

So you would say:

• интересный дуэт = an interesting duet
• новый дуэт = a new duet

Its gender affects adjective agreement and some pronoun choices, but not the meaning itself.

Yes, the sentence is grammatical, but the context matters.

A duet normally involves two performers, so a learner may wonder why Russian says she performs a duet rather than using a plural subject.

This sentence can still make sense if:

• we are talking about her part in the duet,
• the other performer is already known,
• or we are focusing only on her participation.

For example, it could imply:

• she performs a duet with someone
• she is the featured person being discussed

If you wanted to mention both performers, you might say:

• Они исполняют дуэт. = They perform a duet.

So the singular subject is possible; it just puts the spotlight on her.

Yes. Russian can express this idea in different ways, with slightly different nuances.

For example:

• Она исполняет дуэт. = She performs a duet.
• Она поёт дуэтом. = She sings in a duet / she sings as part of a duo performance.

The difference is roughly this:

• исполняет дуэт focuses on the piece being performed
• поёт дуэтом focuses on the manner of singing, that she is singing together with another person

So your sentence is fine, but it is a bit more formal and performance-oriented.

Russian has no articles, so there is no direct equivalent of a, an, or the.

That means дуэт can mean:

• a duet
• the duet

Context decides which one is meant.

So Она исполняет дуэт could be translated as either:

• She is performing a duet
• She is performing the duet

depending on the situation.

Yes. Russian word order is more flexible than English word order.

The neutral order here is:

• Она исполняет дуэт.

But other orders are possible for emphasis, for example:

• Дуэт она исполняет.
  This emphasizes the duet
• Исполняет дуэт она.
  This can emphasize she, often in contrast with someone else

Even when the order changes, the cases and verb form still show who is doing what.

So word order in Russian often affects focus and emphasis, not the basic grammar.

The perfective partner is исполнить.

Compare:

• Она исполняет дуэт. = She performs / is performing a duet.
  This is imperfective, so it presents the action as ongoing, repeated, or simply viewed as a process.
• Она исполнит дуэт. = She will perform a duet.
  This is perfective, usually presenting the action as a completed whole in the future.
• Она исполнила дуэт. = She performed / has performed a duet.
  This presents the performance as completed.

So aspect is important:

• исполнять = process / ongoing / repeated
• исполнить = completion / single whole event

The stress is:

• она́
• исполня́ет
• дуэ́т

So the full sentence is pronounced roughly: ана́ испалня́йет дуэ́т

A more careful approximation for English speakers:

• она́ = a-NA
• исполня́ет = ees-pal-NYA-yet
• дуэ́т = doo-ET

The stress matters in Russian, so it is good to learn the words together with their stressed syllables.