In the Active Voice, the Subject (Noun) of a sentence Performsan Action (Verb) on an Object. In the Passive Voice, the Subject (Noun) is Acted Upon (Verb) by an Object. Use of active or passive voice depends on what emphasis you want in your writing. Active voice emphasizes the doer of the action; passive voice emphasizes the recipient of the action.
Examples: To switch between passive and active voice, the noun in the object position must change places with the noun in the subject position. Edit the sentence accordingly.
Notes: It is always good practice to write in the active voice unless your instructor says otherwise. However, please keep in mind that passive voice is NOT WRONG!
Passive voice is used to draw attention to the action rather than the doer of the action. For example, many scientific reports are written in the passive voice to emphasize the results of the experiment rather than the experiment itself.