Of course, sometimes using passive voice is necessary to emphasis facts or in scientific writing, but it often detracts from the power of a sentence, and ultimately the paper.  

I recognize this problem, because I am guilty of using passive voice way too much.

If you recognize in a tutoring session that a student frequently uses “to be” forms of verbs instead of active, diverse, and interesting verbs, they are victims of passive voice.  Often these wordy papers lack punch in passages containing passive voice.

As a tutor, you could show the tutee one example of passive voice in their paper and explain the specifics.  Then, you can ask the tutee to underline or highlight all of the “to be” verbs either in a passage or on their whole paper.  This shouldn’t take that long.  You could then work with your tutee to fix a few example of passive voice.  After you make some of these sentences active, the tutee can fix the other examples on their own, and they have already marked the issues, so they will know where to fix the paper by themselves.

Tutor: I’ve noticed that you use quite a bit of passive voice in this paper. Do you know what that is?

Tutee: Nope.

Tutor: Well, some of your sentences don’t have active verbs.  Sometimes passive voice can be used to emphasize certain parts of a paper, but often weighs down a paper with unnecessary wordiness.  

A example of an active sentence:”I threw the ball to Fido”  or “William Faulkner wrote Sanctuary.” 

An example of a passive sentence: “The ball was thrown by me to Fido” or “Sanctuary was written by William Faulkner.”

Do you see why the first sentence has more punch?

Tutee: Yeah that makes sense I guess.

Tutor: To find the passive voice in your paper we can highlight the “to be” verbs. These areas indicate where you have passive voice. Of course, often you use “to be” as active verbs, but generally “to be” verbs are boring and drag down the paper.  So even in the areas where you don’t use passive voice with “to be” verbs you might want to change the verbs if possible.

Tutee: Okay cool. *starts highlighting “to be” verbs and their constructions*