Он выполняет приказ.

Выполнять means to carry out, fulfill, perform, execute. It is a very natural verb with things like:

• приказ = order, command
• задание = assignment/task
• обязанность = duty
• план = plan

So Он выполняет приказ means he is carrying out or obeying an order.

Using делает here would sound wrong, because Russian does not say делать приказ for carry out an order.

It is present tense, 3rd person singular of выполнять.

That means:

• я выполняю = I carry out
• ты выполняешь = you carry out
• он/она выполняет = he/she carries out

So выполняет matches он.

Выполняет comes from выполнять, which is imperfective.

That matters because the imperfective can describe:

• an action happening now: He is carrying out the order
• a repeated or habitual action: He carries out the order / He obeys orders
• a process, without focusing on completion

The perfective partner is выполнить. Compare:

• Он выполняет приказ = He is carrying out the order / He carries out the order
• Он выполнит приказ = He will carry out the order
• Он выполнил приказ = He carried out the order / He has carried out the order

Yes. Russian present-tense imperfective often covers both meanings.

English forces you to choose between:

• He is carrying out the order for something in progress
• He carries out the order for a more general or habitual statement

Russian often leaves that to context. So Он выполняет приказ can mean either one.

Because приказ is the direct object, so it goes in the accusative case.

But here is the key point: for masculine inanimate singular nouns, the accusative looks exactly like the nominative.

So:

• nominative: приказ
• accusative: приказ

That is why the form does not change.

Compare that with an animate masculine noun, where the accusative usually matches the genitive:

• Я вижу солдата = I see the soldier

But with an inanimate noun:

• Я вижу приказ = I see the order

Russian has no articles.

So приказ can mean:

• an order
• the order

The context tells you which one is meant.

That is completely normal in Russian. English learners often want a separate word for the, but Russian simply does not use one.

No. In the present tense, the verb does not show gender.

The form выполняет can mean:

• he carries out
• she carries out
• sometimes even it carries out, depending on context

The gender comes from the pronoun он.

Compare:

• Он выполняет приказ = He carries out the order
• Она выполняет приказ = She carries out the order

Gender shows up on the verb in the past tense, not the present:

• Он выполнял приказ = He was carrying out the order
• Она выполняла приказ = She was carrying out the order

Sometimes yes, but it depends on context.

Russian often omits subject pronouns when the subject is already clear from the situation or previous sentence. So you might hear:

• Выполняет приказ.

But by itself, that does not tell you whether the subject is he or she, because выполняет is the same for both in the present tense.

So in an isolated sentence, Он выполняет приказ is the clearest form.

Yes. Russian word order is flexible, but different orders change the emphasis, not the basic meaning.

The most neutral order here is:

• Он выполняет приказ.

Other possibilities:

• Приказ он выполняет.
  This emphasizes the order: It is the order that he is carrying out.

• Выполняет он приказ.
  This is more marked and contrastive, something like: He is carrying out the order, actually.

So the original sentence is the safest and most neutral version.

No. This is a very important vocabulary point.

Приказ means order in the sense of a command, especially an official, military, or hierarchical one.

It does not mean:

• an order in a restaurant/shop → заказ
• orderliness / tidiness / order as arrangement → often порядок

So:

• выполнять приказ = carry out an order/command
• сделать заказ = place an order
• навести порядок = put things in order / tidy up

The perfective verb is выполнить.

So the sentence changes like this:

• Он выполняет приказ. = He is carrying out the order / He carries out the order
• Он выполнит приказ. = He will carry out the order
• Он выполнил приказ. = He carried out the order / He has carried out the order

The imperfective выполнять focuses on the process or repeated action.
The perfective выполнить focuses on completion.

The stress is:

• Он выполня́ет прика́з.

A simple pronunciation guide:

• Он = on
• выполня́ет = roughly vypol-NYA-yet
• прика́з = pri-KAZ

The most important thing for a learner is to remember the stressed syllables:

• выполня́ет
• прика́з

Stress matters in Russian, so it is worth learning words together with their stress.