Many Persian verbs are "compound verbs," created by pairing a noun or adjective with a light verb. Two of the most essential light verbs are شدن (to become) and کردن (to do). By swapping one for the other, you can easily express whether an action happened on its own, or if someone deliberately caused it.
Things Happening on Their Own (شدن)
When an action happens naturally, accidentally, or when you are just describing a change of state without focusing on who caused it, Persian uses the light verb شدن. In these "intransitive" sentences, the thing undergoing the change is the subject of the sentence.
Deliberate Actions (کردن)
If you want to say that someone deliberately caused that exact same action to happen, swap شدن with کردن. This creates a "transitive" verb. The person performing the action becomes the subject, and the item being affected becomes the direct object (often followed by the specific object marker را).
Common Transitivity Pairs
This شدن / کردن pairing is extremely common in everyday Persian, especially when talking about fixing, breaking, or changing the state of household objects and vehicles. Once you learn a noun or adjective, you get two verbs for free.
For example, turning appliances on:
If a window shatters from pressure, use خرد شدن. If a mechanic intentionally smashes an old battery, use خرد کردن.
The exact same logic applies to repairing things. An object getting repaired uses شدن, while the act of someone actively repairing it uses کردن.