Заполните бюллетень.

Заполните is the imperative form of заполнить, which means to fill in / to fill out / to complete. In this sentence, it is giving an instruction: Fill out ...

Because заполнить is a perfective verb, the idea is fill it out completely, not just be filling it out.

The ending -ите marks the imperative for either:

• you (plural), or
• you (formal singular)

So Заполните бюллетень. can mean:

• Fill out the ballot. said to one person politely/formally
• Fill out the ballot. said to several people

This is very common in instructions, announcements, and official situations.

Yes, it sounds formal or neutral-polite.

Russian has two main ways to say you:

• ты = informal singular
• вы = formal singular or plural

Заполните matches вы.
If you were speaking casually to one friend, you would usually say Заполни бюллетень.

Бюллетень is in the accusative case because it is the direct object of the verb: it is the thing being filled out.

Here, the accusative form looks the same as the nominative form because:

• бюллетень is masculine
• it is inanimate

For many masculine inanimate nouns in Russian, nominative = accusative in the singular.

So:

• бюллетень = nominative
• бюллетень = accusative

Same spelling, different grammatical role.

This is a question about aspect.

• заполните comes from заполнить (perfective)
• заполняйте comes from заполнять (imperfective)

In commands, the difference is often:

• заполните = fill it out / complete it
• заполняйте = fill it out / be filling it out, often focusing more on the process, repeated action, or general instruction

In official instructions for a single complete action, заполните is very natural because the goal is the completed result.

The stress is:

• заполни́те
• бюллете́нь

A simple pronunciation guide:

• заполни́те ≈ za-pal-NEE-tye
• бюллете́нь ≈ byu-lee-TENʹ

A few notes:

• бю sounds like byu, but with a softened b
• the double лл is spelled with two л, though in normal speech it is not dramatically lengthened
• the final ь does not make its own sound; it softens the preceding consonant

The soft sign ь shows that the preceding consonant is soft (palatalized).

In бюллетень, the final нь is pronounced softly.
So the word ends with a soft n sound, not a hard one.

This is important in Russian because soft and hard consonants can distinguish words and grammatical forms.

Yes. Бюллетень can have several meanings depending on context, such as:

• a ballot
• a bulletin
• sometimes a specific official document, depending on context

In the sentence Заполните бюллетень., the intended meaning is usually clear from the situation. For example, at a polling station it would mean ballot.

Yes, Russian word order is more flexible than English word order because case endings show grammatical roles.

The neutral order here is:

• Заполните бюллетень.

You might also hear something like:

• Бюллетень заполните.

That changed order can add emphasis or sound more context-dependent, but the basic meaning stays the same. In most textbook or official instruction contexts, Заполните бюллетень. is the most straightforward version.