Learn Hardcore Russian: Каждый пассажир должен сам проверять своё место в билете. - Each passenger must check their seat in the ticket themselves.

In Russian, каждый (each / every) is grammatically singular, even if logically it refers to many people. The verb and other agreeing words must therefore be singular too.

Каждый пассажир должен… – Each passenger must… (singular: one passenger at a time)
Все пассажиры должны… – All passengers must… (plural: all passengers together)

So you use должен (3rd person singular, masculine) because it agrees with каждый пассажир (singular, masculine), not with the idea of “all passengers.”

What exactly does сам mean here, and why is it needed?

Сам means himself / herself / themselves and is used for emphasis: “do it yourself, personally, not relying on someone else.”

In this sentence:

Каждый пассажир должен сам проверять…
= Each passenger must personally check… / must check for themselves…

If you remove сам:

Каждый пассажир должен проверять своё место в билете.
= Grammatically fine; it just loses the emphasis on “personally”.

Position nuance:

должен сам проверять – slightly stronger on сам (“must themselves be the ones who do the checking”).
должен проверять сам – emphasis moves a bit toward contrasting with others checking (e.g. “not the conductor”).

All of these are possible; the meaning is very close, but сам always adds the “personally/by oneself” nuance.

Why is it своё место, not его место or её место?

Свой / своя / своё / свои is the reflexive possessive pronoun: it usually means one’s own and refers back to the subject of the clause.

Here, the subject is каждый пассажир, so:

Каждый пассажир должен сам проверять своё место…
= Each passenger must check *their own seat…*

If you say:

его место – his seat (some particular male person, not necessarily the subject)
её место – her seat

Using своё makes it clear that each passenger is checking their own seat, not someone else’s. That is exactly the meaning we want here.

Also note agreement:

место is neuter singular → we use своё (neuter singular form of свой).

Why is it место в билете? Literally “seat in the ticket” sounds strange in English.

Yes, word‑for‑word it looks odd in English, but in Russian this is a normal way to phrase it.

Место в билете literally means the seat as specified in the ticket – the seat number that is written in the ticket.

You could think of it as:

место, указанное в билете – the seat indicated in the ticket

Other natural variants in Russian:

место по билету – the seat according to the ticket
место в вашем билете – your seat on the ticket

So в билете is used because the information about the seat is written in the ticket’s text.

Why is the preposition в used in в билете, and not на билете or something else?

With documents, Russian commonly uses в + prepositional to mean “in, inside (the contents of)”:

написано в книге – written in the book
в договоре указано – stated in the contract
в билете указано – indicated in the ticket

So место в билете means the place/seat in the ticket (in the text of the ticket).

На билете would literally be “on the ticket” (physically on its surface) and sounds wrong here, unless you’re talking about something printed on the outside surface of the ticket in a very physical sense (even then, в билете is still more idiomatic for the information).

Why is it проверять (imperfective), not проверить (perfective)?

Aspect choice reflects how the action is viewed:

проверять (imperfective) – process, repeated/habitual action, general rule
проверить (perfective) – a single, complete check, one time

Rules, instructions, and habits in Russian usually use the imperfective:

Нужно всегда проверять документы. – You should always check documents.
Студенты должны регулярно посещать лекции. – Students must regularly attend lectures.

So:

Каждый пассажир должен сам проверять своё место в билете.
= Each passenger must (as a rule, whenever they travel) check their seat in the ticket.

If you said:

…должен сам проверить своё место в билете.
That would sound more like a one-time obligation in a specific situation: must check (once) now / this time. Both are grammatical; the given sentence is more like a general instruction.

Why is it каждый пассажир and not something like каждого пассажира?

Каждый normally takes a singular nominative noun:

каждый человек – each person
каждый студент – each student
каждый пассажир – each passenger

We use nominative here because каждый пассажир is the subject of the sentence: Each passenger must…

If you see каждого пассажира, that’s the genitive form, needed in other structures:

Я знаю каждого пассажира. – I know each passenger. (object → genitive)
Билеты проверяют у каждого пассажира. – They check tickets of each passenger.

So in your sentence, nominative (каждый пассажир) is correct, since that noun phrase does the action (must check).

Why is the verb in the masculine form (должен), if “passenger” can be male or female?

In Russian, many nouns for people have a grammatical gender that is fixed and does not change with the real person’s gender.

Пассажир is grammatically masculine, so adjectives and related forms agree in masculine:

каждый пассажир (not каждая пассажир)
пассажир должен (not должна)

This is true even if we are also talking about female passengers in reality. Russian often uses masculine forms in such generic or mixed-gender statements.

If you specifically meant only women, you would usually say:

Каждая пассажирка должна… (пасса́жирка is the feminine form)

Could we leave out своё and just say проверять место в билете? Would it change the meaning?

You can omit своё:

Каждый пассажир должен сам проверять место в билете.

This is grammatically fine and would usually still be understood as “their own seat” from context. However:

своё explicitly clarifies that the seat belongs to that passenger, not some other seat in the ticket (for example, if a ticket lists several seats, or you’re thinking about checking other people’s seats).

So:

With своё – clearly one’s own seat.
Without своё – still likely understood that way, but slightly less explicit and less natural in careful, instructional language.

Using своё место feels more complete and idiomatic in this kind of rule/instruction.