Learn Hardcore Russian: Мы посетили больницу, чтобы навестить больного дедушку. - We visited the hospital to see our sick grandfather.

The sentence is divided into two parts: a main clause and a subordinate purpose clause. The main clause "Мы посетили больницу" means "We visited the hospital." The subordinate clause "чтобы навестить больного дедушку" explains the purpose of that visit—"in order to visit the sick grandfather."

Why is there a comma before the word чтобы?

In Russian, subordinate clauses that describe purpose—introduced by words like чтобы—are set apart from the main clause with a comma. This punctuation signals that the following phrase explains the reason behind the action in the main clause.

What is the difference between the verbs посетили and навестить in this context?

Посетили is used to indicate that someone visited a location (in this case, the hospital). Навестить is specifically used when visiting a person, often implying a personal or caring visit. Here, the speaker visited the hospital (using посетили) with the purpose of visiting their sick grandfather (using навестить).

Why is the noun больницу in the accusative case?

The noun больницу is in the accusative case because it serves as the direct object of the verb посетили. In Russian, direct objects that receive the action of a verb are typically placed in the accusative case.

Why is the subordinate clause introduced by чтобы followed by the infinitive навестить, instead of a conjugated verb?

When expressing purpose with чтобы, Russian often uses an infinitive to clearly state the intended action. In this sentence, навестить in its infinitive form concisely explains why the hospital was visited, without the need for repetition of the subject.

How does the adjective больного agree with the noun дедушку, and why is it used in that form?

The adjective больного means "sick" and describes the noun дедушку (grandfather). Since дедушка is a masculine animate noun used as a direct object, both the adjective and the noun appear in the accusative case. In Russian, the form больного дедушку correctly shows agreement in gender, number, and case.