В каюте две койки.

In Russian, the verb to be is usually omitted in the present tense.

So:

• В каюте две койки. = There are two bunks in the cabin.
• Literally: In the cabin two bunks.

Russian does this very often:

• Он врач. = He is a doctor.
• Здесь ресторан. = There is a restaurant here.

You can sometimes see есть in similar sentences, as in В каюте есть две койки, but in many simple statements it is left out.

Because after в when it means in / inside, Russian usually uses the prepositional case.

The base form is:

• каюта = cabin

After в for location:

• в каюте = in the cabin

So this is:

• каюта → nominative singular
• каюте → prepositional singular

Compare:

• в доме = in the house
• в комнате = in the room
• в каюте = in the cabin

Yes. в can mean either in or into, depending on whether the sentence shows location or motion.

Here it shows location:

• В каюте две койки. = There are two bunks in the cabin.

So it uses the prepositional case: в каюте.

If you were talking about motion into the cabin, you would normally use the accusative:

• в каюту = into the cabin

Compare:

• Я в каюте. = I am in the cabin.
• Я иду в каюту. = I am going into the cabin.

Because койка is a feminine noun.

Russian has two forms of two in the nominative:

• два for masculine and neuter nouns
• две for feminine nouns

So:

• два стола = two tables
• два окна = two windows
• две книги = two books
• две койки = two bunks

Since койка is feminine, you need две.

After the numbers 2, 3, 4, Russian nouns usually go into the genitive singular.

The dictionary form is:

• койка = bunk, berth, cot

After две:

• две койки

This is a very important pattern:

• два стола = two tables
• три книги = three books
• четыре комнаты = four rooms
• две койки = two bunks

So even though the English meaning is plural, the Russian noun after 2/3/4 is usually in a form that is historically/genetically the genitive singular.

Not exactly.

• кровать = bed
• койка = bunk, berth, cot, simple bed

In the context of a ship or train cabin, койка is especially natural because it suggests a berth/bunk rather than a regular home bed.

So in В каюте две койки, койки is a very suitable word for a cabin.

Yes, the word order sounds natural for introducing what exists in a place.

• В каюте две койки.
• Literally: In the cabin, two bunks.

This is a common Russian pattern for an existence/location statement:

• place first
• then what is there

It answers the question What is in the cabin?

Other word orders are possible, but they may shift the emphasis:

• В каюте две койки. = neutral, natural
• Две койки в каюте. = stronger focus on two bunks
• В каюте есть две койки. = explicitly says there are

Yes, absolutely.

Both are correct:

• В каюте две койки.
• В каюте есть две койки.

The version without есть is very common and often more neutral.

The version with есть can sound a bit more explicit, like There are indeed two bunks in the cabin or The cabin has two bunks.

In many beginner sentences, Russian prefers the shorter version without есть.

Grammatically, after две, койки is in the genitive singular form.

That may feel strange, because in English we think of two bunks as plural. But Russian number phrases work differently:

• 1 → nominative singular
• 2, 3, 4 → genitive singular
• 5 and higher → genitive plural

So:

• одна койка = one bunk
• две койки = two bunks
• пять коек = five bunks

This is one of the most important number patterns in Russian.

The stress is:

• в каю́те
• две
• ко́йки

So the whole sentence is pronounced roughly:

• в каЮте две КОйки

Stress is important in Russian because it is not always predictable from spelling.

In a practical learner sense, yes: две койки is the thing being talked about as existing in the cabin.

But sentences like this are often best understood as existential:

• В каюте = location
• две койки = what exists there

So rather than forcing it into exactly the same grammar pattern as English, it is often easier to think:

• In the cabin — two bunks
• meaning There are two bunks in the cabin

That way, the structure makes more intuitive sense.