In the active, the doer is the subject: Ana painted the house. In the passive, the thing is the subject, and the doer moves to the end or disappears: The house was painted (by Ana). Same action, different focus.
Same situation, two choices. Pick an example.
Ana painted the house.
The camera is on who does it.
The house was painted by Ana.
The camera swaps to what happens to it.
| Rule | Active | Passive |
|---|---|---|
| Subject | The doer | The thing affected |
| Form | The verb in any tense | be (in that tense) + past participle |
| The doer | Always there | by + doer, or left out |
| Typical use | Conversation, stories, when the doer matters | Formal writing, news, processes, unknown doer |
The Mona Lisa _____ by Leonardo da Vinci.
Paste an email or an essay. Clarigram marks the mistakes you actually make, shows the rule behind each one as a picture, and builds your practice from them.
Make the object the subject, put be in the same tense as the active verb, add the past participle, and add by + doer only if it's useful: They built it in 1920 → It was built in 1920.