Quite a few verbs in English change meaning when you add a preposition. You “take out” the trash, for instance, but “take up” a hobby.
In German, you’ll find as much if not more variation on this theme. However, the prepositions most often come in the form of prefixes to the verb.
|to break||to break off|
|to hold||to bear, to endure|
These prefixes can be either separable (the prefix moves to the end of the clause) or inseparable (the prefix is treated as part of the base verb).
Wir fahren heute morgen ab. (separable prefix verb: abfahren)
We set off tomorrow morning.
The prefix reattaches when the verb is conjugated to the perfect.
Sie sind gestern abgefahren.
They left yesterday.