Ангел и принц вошли в зал.

Because the subject is Ангел и принц — two people joined by и (and). In Russian, the past tense agrees with the subject in number, so with two subjects you use the plural form:

• вошёл = he entered
• вошла = she entered
• вошло = it entered
• вошли = they entered

So Ангел и принц вошли is the natural plural agreement.

The dictionary form is войти.

вошли is the past plural form of войти. So when you look it up in a dictionary, you would search for войти, not вошли.

войти is perfective.

That means it presents the action as completed: they entered the hall, and the action is viewed as a finished event.

The imperfective partner is входить. Compare:

• вошли в зал = they entered the hall
• входили в зал = they were entering / used to enter / entered repeatedly, depending on context

In this sentence, the idea is a single completed event, so вошли is the right choice.

Because Russian uses different cases after в depending on whether you mean motion into something or location inside something.

• в + accusative = into, movement toward the inside
• в + prepositional = in, location

So:

• в зал = into the hall
• в зале = in the hall

Since the sentence describes movement into the hall, Russian uses в зал.

It is accusative singular.

The preposition в takes the accusative when it means movement into a place. So in в зал, the noun is in the accusative.

Because зал is a masculine inanimate noun.

For many masculine inanimate nouns in Russian:

• nominative singular = accusative singular

So:

• зал = hall (nominative)
• в зал = into the hall (accusative, but same form)

That is why the form does not visibly change here.

They are in the nominative case because they are the subject of the sentence.

The sentence tells us who performed the action:

• Ангел
• принц

Both are singular nouns, but together they form a compound subject, which is why the verb is plural.

Because Russian does not have articles.

English must choose between a/an and the, but Russian usually leaves that idea to context. So Ангел и принц can mean:

• an angel and a prince
• the angel and the prince

The surrounding context tells you which interpretation is intended.

Yes. Russian word order is fairly flexible because case endings help show what each word is doing.

The given order, Ангел и принц вошли в зал, is a normal neutral way to say it.

But other orders are also possible, for example:

• В зал вошли ангел и принц — puts more focus on into the hall
• Вошли в зал ангел и принц — possible in a more narrative or stylistic context

The basic meaning stays the same, but the emphasis can shift.

Because войти specifically means to go in / to enter.

The prefix в- adds the idea of movement into something. So:

• идти = to go, to walk
• войти = to go in, to enter

If you want to say that they moved from outside to inside the hall, войти is the natural verb.

Russian past tense is usually formed from the verb stem plus endings that show gender in the singular and number in the plural.

For войти, the past forms are:

• вошёл — masculine singular
• вошла — feminine singular
• вошло — neuter singular
• вошли — plural

So in this sentence, the plural ending -ли is used because the subject is plural.

The main stress is:

• А́нгел
• при́нц
• вошли́
• зал

A rough pronunciation guide could be:

• А́нгел ≈ AHN-gel
• при́нц ≈ preents
• вошли́ ≈ va-shLEE
• зал ≈ zahl

So the whole sentence sounds roughly like:

AHN-gel ee preents va-shLEE f zahl

The в before зал is often pronounced closer to f because of the following consonant.