The preposition anhand
When explaining how you came to a conclusion or how you identify something, you use the preposition anhand ("on the basis of" or "by means of"). This is especially useful in science and nature, such as when identifying plants by their physical traits.
| on the basis of / by means of | anhand |
Like many formal prepositions, anhand always requires the noun that follows it to be in the genitive case.
anhand with masculine and neuter nouns
For masculine and neuter nouns in the genitive case, the definite article changes to des. Additionally, the noun itself usually adds an -s or -es to the end.
| One recognizes the tree by means of the leaf. | Man erkennt den Baum anhand des Blattes. |
anhand with feminine and plural nouns
For feminine and plural nouns, the genitive definite article is der. Unlike masculine and neuter nouns, the noun itself does not change its ending.
| One recognizes the older trunk by means of the bark. | Den älteren Stamm erkennt man anhand der Rinde. |
If you are using multiple nouns as evidence, you simply put all of them into the genitive case.
| One distinguishes the trees by means of the bark and the branches. | Man unterscheidet die Bäume anhand der Rinde und der Zweige. |
Using demonstrative articles
You will often point to a specific feature using a demonstrative article like dies- ("this"). Because it must also take the genitive case, it becomes dieses for masculine and neuter nouns, and dieser for feminine and plural nouns.
| On the basis of this feature, we distinguish the plants. | Anhand dieses Merkmals unterscheiden wir die Pflanzen. |
Notice that the entire phrase (Anhand dieses Merkmals) can occupy the first position in the sentence. As always in a regular German main clause, the conjugated verb (unterscheiden) takes the second position.