Der Infinitivsatz: Sein with “Zu”

I. Theory

In German, we find many instances where zu + infinitive is used in conjunction with the verb sein. In these instances, there is often a preceding adjective before the infinitivsatz. The infinitivsatz is separated from the main clause by a comma.

Es ist schwierig, eine Sprache ohne Wörterbuch zu lernen. It is difficult to learn a language without a dictionary. Manchmal ist es leicht, deutsche Wörter zu erkennen. Sometimes it is easy to recognize German words. Samstags ist es bei den meisten Restaurants notwendig, einen Tisch zu reservieren. It’s necessary to reserve a table at most restaurants on Saturdays.

II. Conveying the Passive

However, a preceding adjective isn’t always necessary. Here we see examples where sein + zu + infinitive convey the passive voice.