In able to express a sentence in an active voice, the subject should be the one doing the action...
Example:
-Rex passed the test...
-Alexandra taught me the french language...
The inverse of active voice is passive..
The predicate or the action is stated first before the subject, but there are still rules to follow..
Example:
-The test was passed by Rex.
-The person who taught me french language was Alexandra.
You can research on passive voice so that it can be clear for you...
I hope I had helped you!
