I am so confused about how to change passive to active. How do I say:
I was inducted into the National Honor Society
in active voice?
Promoting my comments to an answer.
A sentence in active voice needs a subject. Here whoever did the inducting. In addition to Jasper's suggestion another possibility might be
The selection committee inducted me into the National Honor Society.
The uncertainty here is that I invented that subject. This reflects the fact that in a sentence like this the subject is often of marginal interest only, and the use of passive voice is thus somewhat indicated. Compare with a press release like
Today the star player X was inducted into the Hockey Hall of Fame.
The fans are only interested in the fact that their hero was (finally) honored this way. They couldn't care less about who made the decision.
Passive voice has a form like:
<Event> happened to <patient>.
<Patient> was <verb>ed by <actor>.
The original post's example is:
I was inducted into the National Honor Society.
Active voice has a form like:
<Actor> <verb>ed <patient>.
Here are two active versions of the original post's example:
The National Honor Society inducted me.
I joined the National Honor Society.