Сегодня курс в банке ниже, чем вчера.

Today the rate at the bank is lower than yesterday.

Breakdown of Сегодня курс в банке ниже, чем вчера.

• вчера: yesterday
• сегодня: today
• в: at
• чем: than

Questions & Answers about Сегодня курс в банке ниже, чем вчера.

Why is курс in the nominative case?

Because курс is the subject of the sentence — the thing being described.

In Сегодня курс в банке ниже, чем вчера, the sentence is saying something about the rate. That makes курс nominative singular.

A very literal structure is:

Today the rate in the bank is lower than yesterday.

In Russian, the subject usually appears in the nominative unless something else in the sentence changes that.

Why is there no word for is?

Russian normally omits the present-tense form of to be.

So where English says:

The rate is lower

Russian simply says:

Курс ниже

This is completely normal. In the present tense, Russian usually does not use a separate word for is / am / are.

Compare:

• Он дома = He is at home
• Курс ниже = The rate is lower

What case is в банке, and why?

В банке is in the prepositional case because it follows в in the meaning of in / at a place.

• dictionary form: банк
• prepositional singular: в банке

So:

• в банке = in the bank / at the bank

This is a standard pattern:

• в магазине = in the store
• в городе = in the city
• в банке = in the bank