Learn Hardcore Russian: Интернет не заменяет живого разговора. - The internet does not replace a live conversation.

A learner might expect the direct object to be in the accusative, and normally that is true. But after a negated verb, Russian often allows or prefers the genitive of negation.

So:

affirmative: Интернет заменяет живой разговор
negative: Интернет не заменяет живого разговора

This is a very common Russian pattern, and it often sounds a bit more general or abstract in negative statements.

Breakdown:

живой → живого
разговор → разговора

Both words change because the adjective must agree with the noun.

Could you also say Интернет не заменяет живой разговор?

Yes, that is also grammatically possible in modern Russian.

So both of these can occur:

Интернет не заменяет живой разговор — accusative
Интернет не заменяет живого разговора — genitive after negation

The version with genitive can sound a bit more idiomatic, generalized, or formal in this kind of statement. The accusative version is more straightforward and may feel more concrete.

For a learner, the important thing is:

both exist
the sentence you were given uses a very normal Russian pattern with negation

Why is the verb заменяет?