Двое соседей пришли сразу.

Двое is a collective numeral, while два is a regular cardinal numeral.

Russian often uses collective numerals like двое, трое, четверо with:

• groups of people, especially men or mixed groups
• children
• nouns that only exist in the plural
• some paired items

So двое соседей means two neighbors as a group.

A learner should know that два соседа is also possible, but двое соседей has a more collective feel.

Yes, you can.

Both двое соседей and два соседа are grammatical, but they are not exactly identical in feel:

• двое соседей = emphasizes the pair as a group
• два соседа = a more straightforward counting phrase

In many contexts, the difference is small. A native speaker might choose one or the other based on style, habit, or emphasis.

After двое, the noun usually goes in the genitive plural.

So:

• двое кого? → соседей

This is why you get:

• двое друзей
• двое студентов
• двое соседей

This is one of the patterns you simply need to learn with collective numerals.

In this sentence, двое соседей is the subject, so the whole phrase is in the nominative function.

But inside that subject phrase:

• двое is the numeral
• соседей appears in the genitive plural, because that is the form collective numerals require

So the phrase acts like a nominative subject overall, even though the noun itself is genitive plural.

Because the subject refers to two people.

In the past tense, Russian verbs agree in:

• gender if the subject is singular
• number if the subject is plural

So:

• пришёл = he came
• пришла = she came
• пришло = it came
• пришли = they came

Since двое соседей means more than one person, the verb is plural: пришли.

Usually, yes.

Двое is normally used for:

• two male people
• a mixed-gender group

It is not normally used for two adult females when a regular feminine counting form is available.

So:

• двое соседей usually suggests two male neighbors or a mixed pair
• for two female neighbors, Russian would normally say две соседки

Сразу can mean things like:

• immediately
• right away
• all at once / together, depending on context

In Двое соседей пришли сразу, the most natural reading is often:

• Two neighbors arrived at once / together or
• Two neighbors came immediately

The exact meaning depends on context. If the surrounding situation is about timing, it may mean immediately. If it is about multiple people appearing together, it may mean at the same time.

No, Russian word order is fairly flexible.

The sentence Двое соседей пришли сразу is neutral and natural. But other orders are possible, for example:

• Сразу пришли двое соседей.
• Пришли сразу двое соседей.

These versions can shift emphasis:

• putting сразу first highlights the timing
• putting двое соседей later can make the arrival itself sound more news-like

The basic meaning stays the same, but the focus changes.

Пришли is the past tense of прийти, which means to arrive / to come.

Russian distinguishes between:

• идти = to be going, to go on foot in progress
• прийти = to come, to arrive

So:

• Они идут. = They are walking / They are on their way.
• Они пришли. = They came / They arrived.

In this sentence, the action is completed, so пришли is the correct choice.