How can I avoid using passive voice?
The obvious (but perhaps not very helpful) answer is:
A sentence in the passive voice has a subject what is the recipient of the action.
#color(white)("XXX")Mr. Bodey was killed by Col. Mustard in the library.
To write this in the active voice, make the performer of the action the subject; for example:
Sometimes this is not as simple; for example if the performer of the action is not known. In this case we can (usually) admit to lack of knowledge and use a non-specific identifier as the subject.
Speak/write in E-Prime, and avoid all forms of "to be."
Forms of the verb "to be"--am, is, are, was, were, be, being, been, etc.--function as passive verbs. They describe an action that could be imputed to a houseplant as easily as to a human being. A variant on mainstream English called "E-Prime" seeks to avoid these verbs entirely. The result clarifies the English language to the point that one cannot avoid responsibility for one's actions; no E-Prime equivalent for "mistakes were made" exists. Give it a try!