Learn Hardcore Russian: Прежде чем приглашать гостей, нужно подготовить комнату и убрать пыль. - Before inviting guests, you need to prepare the room and remove dust.

Прежде чем is a conjunction meaning “before (doing something).” It introduces a subordinate time clause. Here, Прежде чем приглашать гостей tells you which action must wait until after the main tasks are completed.

Why is приглашать in the infinitive form?

After Прежде чем, Russian often uses the infinitive to give concise, general instructions. It’s a shortcut for a full clause like Прежде чем вы пригласите гостей. The infinitive keeps the sentence impersonal and to-the-point.

Why do we use нужно here? Could we say надо instead?

Both нужно and надо are impersonal words expressing necessity and are followed by an infinitive. They are interchangeable in meaning:

нужно подготовить комнату
надо подготовить комнату
нужно may sound slightly more neutral or formal; надо is more colloquial.

Why is there no explicit subject in the main clause?

Impersonal constructions with нужно/надо don’t require a grammatical subject. The person responsible is implied by context (e.g., “we” or “one”). If you want to specify, you can say Нам нужно подготовить комнату..., but it’s not obligatory.