Карта доступа открывает кабину для звонков.

Карта is the main noun, and доступа is in the genitive singular.

This is a very common Russian pattern:

• карта доступа = access card
• literally: card of access

English often uses one noun directly before another noun (access card, phone booth, office door). Russian usually does this with:

• noun + noun in the genitive

More examples:

• номер телефона = phone number
• центр города = city center
• чашка чая = cup of tea

So here:

• карта = card
• доступ = access
• доступа = of access

That makes карта доступа a natural way to say access card.

Открывает is the 3rd person singular present tense of открывать.

So grammatically it means:

• (it/he/she) opens
• here: the access card opens / unlocks ...

Because карта is singular, the verb is singular too:

• карта открывает = the card opens

A useful point for learners: Russian often uses открывать / открыть not only for physically opening something, but also for giving access or unlocking something.

So in context, карта доступа открывает кабину can mean something like:

• the access card opens the booth
• the access card unlocks the booth
• the access card gives access to the booth

Also, открывает is from the imperfective verb открывать. In the present tense, imperfective is normal for a general statement like this:

• Карта доступа открывает... = The access card opens...

If you used the perfective открыть, the future form would be:

• карта доступа откроет... = the access card will open...

Because кабину is the accusative singular form of кабина.

The verb открывать usually takes a direct object — the thing being opened:

• открывать дверь = to open a door
• открывать окно = to open a window
• открывать кабину = to open a booth/cabin

Since кабина is a feminine noun ending in -а, its accusative singular changes to -у:

• nominative: кабина
• accusative: кабину

So:

• Карта доступа открывает кабину
  = The access card opens the booth

This is one of the most important beginner patterns in Russian: for many feminine nouns ending in -а, the accusative singular ends in -у.

Because the preposition для requires the genitive case.

So:

• звонки = calls (nominative plural)
• звонков = of calls / for calls (genitive plural after для)

That gives:

• для звонков = for calls

This is a fixed grammar rule:

• для + genitive

Examples:

• для детей = for children
• для работы = for work
• для машины = for the car

So in your sentence:

• кабину для звонков = a booth for calls

Without для, звонков would not fit naturally here.

It is understandable, but it is a bit more literal and descriptive than the most common everyday phrase.

A more standard expression would often be:

• телефонная будка = phone booth
• sometimes телефонная кабина = telephone booth

But кабина для звонков is still grammatically correct and understandable as:

• a booth/cabin for making calls

So a learner should know two things:

1. The grammar is fine.
2. A native speaker might choose a more idiomatic noun phrase in real life.

In other words, this sentence works well for studying grammar, even if another phrase might sound more natural in everyday speech.

Yes, absolutely.

Russian, like English, can use an inanimate noun as the subject when it is the thing that causes an action or has a function.

Examples:

• Ключ открывает дверь. = The key opens the door.
• Пароль открывает доступ. = The password opens access.
• Карта открывает вход. = The card opens/unlocks the entrance.

So карта доступа открывает... is completely normal grammatically.

In English, we also do this:

• The key opens the lock.
• This button opens the menu.

Russian works the same way here.

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

The neutral order here is:

• Карта доступа открывает кабину для звонков.

But you could change the order for emphasis, for example:

• Кабину для звонков открывает карта доступа.
  Emphasis on the booth for calls

• Для звонков карта доступа открывает кабину.
  This is less neutral and more context-dependent, but still possible in the right situation.

Even when the order changes, the cases still show the roles:

• карта = subject
• кабину = object
• для звонков = prepositional phrase meaning for calls

So the meaning usually stays clear.

Yes, singular is possible in principle, but plural sounds more natural here.

• для звонков = for calls
• для звонка = for a call

The plural для звонков sounds like a general-purpose description:

• a booth meant for making calls

The singular для звонка would sound more like:

• for one call
• for a particular call
• for the purpose of making a call in a specific instance

So in a general label or description, Russian often prefers the plural:

• комната для переговоров = room for meetings/discussions
• очки для чтения = glasses for reading
• кабина для звонков = booth for calls

Not always. Открывает is understandable, but depending on the exact situation, a native speaker might choose a more precise verb.

Possible alternatives include:

• отпирает = unlocks
• разблокирует = unlocks/unblocks
• даёт доступ в/к = gives access to
• позволяет войти в = allows entry into

For example:

• Карта доступа отпирает кабину.
• Карта доступа даёт доступ к кабине.

So открывает is not wrong, but it can be slightly broader in meaning. In real usage, the best verb depends on whether the card:

• physically opens something,
• unlocks it,
• or simply grants access.