Here's why:
* Passive voice is a grammatical structure, not a meaning changer. It simply rearranges the sentence to emphasize the action's recipient rather than the actor.
* Every passive sentence has a potential active voice counterpart. The information about the actor might be implied or omitted, but it's always *there* in the sentence's meaning.
Let's look at an example:
Passive: The ball was hit by the batter.
Active: The batter hit the ball.
Even if we omit the actor in the passive voice ("The ball was hit."), the active voice version ("Someone hit the ball") is still possible.
The only reason a passive sentence might *appear* impossible to convert to active voice is if the actor is unknown or irrelevant to the context. For example:
* "The door was left open." (We don't know who left it open)
* "The cake was eaten." (We only care about the cake, not who ate it)
In these cases, we could still technically *form* an active voice sentence, but it would sound awkward or meaningless:
* "Someone left the door open."
* "Someone ate the cake."
However, the *meaning* of the sentences remains the same, and the passive voice simply emphasizes the action and its effect.