Prepositions are words that put the object into a relation with the subject or with another objects. Prepositions are for instance before, after, behind, over, under etc. There are about 160 prepositions in the English language and around the same amount in German. For the time being, we just look at the most important ones.

A man is behind the door. = Ein Mann ist hinter der Tür. The plane lands before 10 a.m. = Das Flugzeug landet vor zehn Uhr. I do it for you. = Ich tue das für Dich. We can do it with you as well. = Wir können das auch mit Euch machen.