Many German verbs come in historical pairs. In these pairs, one verb describes an action that happens on its own (intransitive), while the other verb describes causing that action to happen to a direct object (transitive).
There is a very reliable grammatical pattern to these pairs:
- The intransitive (happening) verb is usually a strong (irregular) verb. Because it often describes a change of state or motion, it typically forms its perfect tense with sein.
- The transitive (causing) verb is a weak (regular) verb. Because it takes a direct object, it forms its perfect tense with haben.
Fallen and Fällen
A classic example is the pair fallen (to fall) and fällen (to fell / cut down).
As the intransitive action, fallen is a strong verb that uses sein in the perfect tense.
| The old tree has finally fallen into the river. | Der alte Baum ist endlich in den Fluss gefallen. |
To describe causing a tree to fall, you use the weak, transitive verb fällen. Notice the vowel shift (from a to ä) and the regular -t participle ending.
| Who felled this big tree? | Wer hat diesen großen Baum gefällt? |
You can see both the strong happening and the weak causing side-by-side in this sentence:
| The tree only falls because the beaver felled it. | Der Baum fällt nur, weil der Biber ihn gefällt hat. |
Sinken and Senken
The exact same pattern applies to sinking. Sinken (to sink) is the strong, intransitive verb.
| The branch sank slowly into the body of water. | Der Ast ist langsam in das Gewässer gesunken. |
If you want to actively sink or lower an object, you use the weak, transitive verb senken. Here, the core vowel shifts from i to e.
| The smart beaver lowers the branch into the body of water. | Der schlaue Biber senkt den Ast in das Gewässer. |
Liegen and Legen
You have likely already encountered this pattern with position verbs. Liegen (to lie / be located) describes a state or outcome, while legen (to lay) describes the active, transitive process of placing an object.
| The beaver laid the wood onto the dam. | Der Biber hat das Holz auf den Staudamm gelegt. |
| Now the wood lies there and sinks slowly. | Jetzt liegt das Holz dort und sinkt langsam. |
Verschwinden and Verschwenden
While their meanings have drifted apart over the centuries, this final pair follows the exact same morphological shift!
Verschwinden (to disappear) is the strong, intransitive verb indicating a change in state.
| The branch disappeared in the pond. | Der Ast ist im Teich verschwunden. |
Meanwhile, verschwenden (to waste) is its weak, transitive counterpart, taking a direct object and using haben for its perfect tense.
| We waste no water from this pond. | Wir verschwenden kein Wasser aus diesem Teich. |
