How do you translate passive voice to active voice?
Specifically, how would you translate the sentence "It can be determined that he is knowledgeable about the technology."
Since there is no real, "active" subject (somebody doing the determining), you can’t use the active voice in that particular case. The "it" is what I like to call a "dummy subject/pronoun", but technically called expletive pronoun or pleonastic pronoun. We have to deal with stuff like this because English isn’t a pro-drop language, in which pronouns can’t be dropped.
Common sentences with "dummy subjects":
It is raining. (Who/What is it???) Spanish (pro-drop): = llueve.
It’s dark outside. (What is it?)
There are 6 cats over here. (There serves as this dummy.) Spanish (pro-drop): Hay seis gatos aquí.
If there were somebody actually determining, you could stick in a real subject. For example: The teacher can determine that he is knowledgeable about the technology.
You can e-mail me with any other questions you have about stuff like this