Agent in Passive Sentences with von

In an active sentence, the subject performs the action. Der Chef (subject) liest (verb) den Bericht (object). In a passive sentence, the object becomes the subject. Der Bericht wird gelesen. But who read it? To add that person back, use the preposition von. This preposition always triggers the Dative case. So, den Bericht becomes the star. Der Chef moves to a secondary role. You are essentially pointing a finger at the cause. It is like a grammar traffic light. It directs the flow of information. You decide who gets the green light.

1. 1Creating these sentences follows a strict logical path. Follow these steps to get it right every time:
2. 2Identify your active subject (the doer) and object (the receiver).
3. 3Move the receiver to the front. This is your new subject.
4. 4Conjugate the auxiliary verb werden based on this new subject.
5. 5Place the preposition von after the conjugated verb.
6. 6Change the original doer into the Dative case.
7. 7Put the past participle (Partizip II) at the very end.
8. 8Example: Die Firma (Subject) kündigt (Verb) den Vertrag (Object).
9. 9Passive: Der Vertrag (New Subject) wird (Werden) von der Firma (von + Dative) gekündigt (Partizip II).

Use this when the doer is important but not the main focus. Imagine you are at a job interview. You want to highlight a project you finished. You might say: "This project was managed by me." In German: Dieses Projekt wurde von mir geleitet. It sounds professional and modest. Use it in news reports for natural disasters. Die Stadt wurde von einem Sturm zerstört. It is perfect for scientific descriptions. Die Daten wurden von dem Computer analysiert. Use it when you want to sound objective. It works well in formal emails and academic writing. Even native speakers use it to avoid sounding too aggressive. Instead of "You broke the vase," say "The vase was broken by you."

Do not use von for tools or instruments. If you use a key to open a door, do not use von. Use durch for the means or the process. Die Tür wurde durch einen Schlüssel geöffnet is technically about the tool. von is reserved for the originator or the cause. This usually means people, animals, or natural forces. Do not use it if the agent is unknown. If someone stole your bike, just say Mein Fahrrad wurde gestohlen. Adding von jemandem is redundant and sounds clunky. Also, avoid it if the sentence gets too long. German sentences can become monsters if you are not careful. Keep it lean and readable.

The biggest trap is the case. Many people use the Accusative after von. Remember: von is always Dative. Always. No exceptions. Von dem Mann, not von den Mann. Another mistake is word order. The past participle must stay at the end. Do not let it wander into the middle of the sentence. Some people forget to conjugate werden correctly. It must match the *new* subject, not the old one. If the new subject is plural, use werden. If it is singular, use wird. Yes, even native speakers mess this up when they are tired. Think of it as a puzzle. Every piece has a specific home.

Compare von with durch. von is for the "who" or the "active cause." durch is for the "how" or the "medium."

• Der Brief wurde von mir geschrieben. (I am the author).
• Der Brief wurde durch die Post geschickt. (The post is the delivery method).

Compare it with the active voice. Active voice is direct and energetic. Passive with von is descriptive and formal. Use active voice for stories and daily chats. Use passive with von for facts and results. It is like choosing between a sports car and a sturdy sedan. Both get you there, but the vibe is different.