Сегодня в магазине нельзя платить картой, поэтому я заплачу наличными.

Today in the store you can’t pay by card, so I will pay in cash.

Breakdown of Сегодня в магазине нельзя платить картой, поэтому я заплачу наличными.

• я: I
• в: in
• магазин: the store
• сегодня: today
• поэтому: therefore
• платить: to pay
• заплатить: to pay
• наличными: in cash
• нельзя: can’t
• карта: card

Questions & Answers about Сегодня в магазине нельзя платить картой, поэтому я заплачу наличными.

Why is в магазине used, and what case is магазине in?

В магазине means in the shop/store. After в meaning location (in/at), Russian uses the Prepositional case, so магазин → в магазине.
(If it were motion into the store, it would be в магазин with the Accusative.)

What does нельзя mean grammatically, and how is it different from не можно?

Нельзя + infinitive is a very common pattern meaning it’s not allowed / it’s impossible to do something. It’s impersonal: there’s no grammatical subject.
Не можно is generally not used in modern standard Russian for this meaning; native speakers use нельзя (or невозможно for “impossible,” запрещено for “forbidden,” etc.).

Why is платить in the infinitive after нельзя?

After нельзя, Russian typically uses the infinitive to name the action that is not allowed/possible:
нельзя платить = one can’t / it’s not allowed to pay.

Why is it платить картой and not something like платить карту?

Because the means/instrument (“by card”) is expressed with the Instrumental case:
карта → картой = with/by card.
So платить картой is “pay by card,” not “pay the card.”

Is картой specifically “bank card,” and can it mean other “cards”?

In everyday Russian, платить картой almost always means pay by (bank) card (debit/credit). Context makes this clear. If you needed to be explicit, you could say банковской картой.

What is the role of поэтому, and why is there a comma before it?

Поэтому means therefore / so and often introduces a result clause. When two independent clauses are connected this way, Russian typically uses a comma:
… нельзя платить картой, поэтому …
The comma marks the boundary between the two clauses.

Why does the second part use я заплачу, and why is it future?

Заплачу is the future tense form of the perfective verb заплатить (“to pay (once), to make the payment”). It expresses a single completed action in the future: I’ll pay (this time).

Why is it заплачу (perfective) instead of буду платить (imperfective)?

Russian chooses aspect based on how the action is viewed:

• заплачу (perfective) = a single, completed payment (the normal choice here).
• буду платить (imperfective) = emphasis on the process or repeated/ongoing paying, which sounds unnatural for a one-time payment at the checkout.

Why is наличными plural, and what case is it?

Наличными is Instrumental plural, used to express the means of payment: pay with cash.
Russian treats “cash (money)” here as a plural idea (“cash funds”), and the fixed adverb-like phrase is платить наличными.

Could the sentence omit я? If yes, why is it included?

Yes, Russian often drops subject pronouns because the verb ending shows the person: заплачу already means “I will pay.”
Я is included for emphasis/contrast: “so I will pay in cash (given the situation).”

Is the word order flexible here? Could parts be rearranged?

Yes, Russian word order is fairly flexible, but it changes emphasis. For example:

• Сегодня в магазине нельзя платить картой… is neutral.
• Сегодня нельзя платить картой в магазине… focuses a bit more on “today it’s not allowed.”
• В магазине сегодня нельзя платить картой… highlights “in the shop (today).”
  The given order sounds natural and conversational.

How do you pronounce/stress the key words: сегодня, нельзя, поэтому, заплачу, наличными?

• сегОдня (stress on О)
• нельзЯ (stress on final Я)
• поэтОму (stress on О)
• заплачУ (stress on final У)
• налИчными (stress on И)