Без проездного нельзя пройти через турникеты.

Because без always requires the genitive.

• без = without
• So проездной changes to проездного

This is a very common pattern in Russian:

• без паспорта = without a passport
• без билета = without a ticket
• без проездного = without a travel pass

So the case here is controlled by the preposition без.

Проездной is short for проездной билет or проездной документ, meaning a travel pass, transport pass, or season ticket.

In modern Russian, the adjective-like form проездной is very often used by itself as a noun. This is common in Russian: an adjective can stand alone when the missing noun is understood.

So:

• проездной билет = travel pass
• проездной = the same thing, in everyday speech

In this sentence, проездного is the genitive singular form of that word.

Нельзя means it is not allowed, it is impossible, or one cannot. It expresses a general rule or impossibility.

So:

• нельзя пройти = one cannot / it is not possible / it is not allowed to pass

If you said не пройти, that would not express the same idea. It would sound incomplete or mean something else depending on context.

Compare:

• Здесь нельзя курить. = You can't smoke here.
• Без билета нельзя войти. = You can't enter without a ticket.

So нельзя is the key word showing prohibition or impossibility.

Пройти is a perfective verb meaning to pass through, to get through, or to go past successfully.

In this sentence, the idea is not general wandering or ongoing motion, but the completed action of getting through the turnstiles.

A rough comparison:

• идти = to be going, to walk
• ходить = to go/walk habitually or back and forth
• пройти = to pass through, to get through

So пройти через турникеты means to get through the turnstiles.

Russian often uses the perfective infinitive after нельзя when talking about whether a completed action is possible or allowed:

• Нельзя войти. = You can't enter.
• Нельзя пройти. = You can't get through.

Because the preposition через normally takes the accusative and means through or across.

• singular: турникет
• plural nominative: турникеты
• plural accusative for inanimate nouns: also турникеты

Since турникеты is an inanimate plural noun, its accusative plural is the same as its nominative plural.

So:

• через турникеты = through the turnstiles

Compare:

• через дорогу = across the road
• через мост = across the bridge
• через дверь = through the door

Турникеты means turnstiles or ticket barriers, such as the gates in a metro, train station, or bus station that only let you through if you have a valid ticket or pass.

Singular:

• турникет = turnstile

Plural:

• турникеты = turnstiles

In this sentence, the plural suggests the barrier area in general, as you would commonly see in a station.

Yes, but that is normal in Russian.

Без проездного нельзя пройти через турникеты does not name a specific subject like you, one, or people. In English, we often translate it with a general subject:

• You can't get through the turnstiles without a pass
• One cannot pass through the turnstiles without a pass

Russian often leaves the subject unstated in general rules, signs, and instructions. The sentence is understood as applying to anyone.

Yes. Russian word order is flexible, and different orders can shift emphasis.

The given sentence:

• Без проездного нельзя пройти через турникеты.

This is a natural, neutral order for a rule or notice.

Other possible orders include:

• Через турникеты нельзя пройти без проездного.
• Нельзя пройти через турникеты без проездного.

These all mean basically the same thing, but the focus changes slightly:

• starting with без проездного emphasizes the condition
• starting with нельзя emphasizes the prohibition
• starting with через турникеты emphasizes the location/path

Yes. Нельзя can cover both ideas, and context tells you which is stronger.

In this sentence, both meanings are close together:

• it is not allowed to pass through the turnstiles without a pass
• you cannot get through the turnstiles without a pass

In a metro station, this usually implies both a rule and a practical fact: the system will not let you through.

Russian has no articles. There is no direct equivalent of English a/an or the.

So без проездного could mean:

• without a pass
• without the pass

In practice, English would usually say without a pass here, because the meaning is general.

Russian expresses definiteness through context rather than articles.

A few natural translations are:

• You can’t get through the turnstiles without a pass.
• You can’t go through the turnstiles without a travel pass.
• No entry through the turnstiles without a pass. (more like a sign)

The Russian sentence is neutral and typical of a public notice or rule.

Yes. The dictionary form проездной is masculine.

Its forms here are:

• nominative singular: проездной
• genitive singular: проездного

That is why after без you see проездного.

Even though in English pass is just a noun, in Russian this word historically has adjective-like endings, and it still declines that way when used as a noun.

A simple pronunciation guide is:

Bez prayezd-NO-va nel-ZYA pray-TI che-REZ toor-nee-KYE-ty

A few helpful notes:

• без = bez
• проездного has stress on -но-: проездно́го
• нельзя́ has stress on the last syllable
• пройти́ has stress on the last syllable
• через usually has stress on the first syllable: че́рез
• турнике́ты has stress on -ке-

If you want to sound natural, the sentence rhythm is roughly:

Без проездно́го нельзя́ пройти́ через турнике́ты.