I’ll give it a shot.
The active voice is generally arranged in subject-verb-object order. Incubus gave us a perfect example of an active voice sentence:
I cannot recognize the passive voice.
For the purposes of this example, let’s regard I as the subject, recognize as the verb, and the passive voice as the object. Strictly speaking, the object isn’t three words (technically, the object is only the noun voice), but if we look at the object as three words long, things should be clearer.
The passive voice “flips” the word order–the object comes first, then the verb (with the help of an auxiliary–we’ll use is in the example), then we bring in a preposition (by), and the subject finally comes last. Here is the above example, rendered in the passive voice:
The passive voice is not recognized by me.
As you can see, it’s a little more complicated than I made it sound, and I won’t get into why I becomes me. But, Incubus, you should have enough linguistic knowledge of English to see what is happening. Let’s look at a few more examples–A and P will stand for Active and Passive, respectively:
*A: John kicked the ball.
P: The ball was kicked by John.
A: I won the tennis match.
P: The tennis match was won by me.
A: Sue plays blackjack in Las Vegas.
P: Blackjack is played by Sue in Las Vegas.*
As you can guess from the last example, the passive voice can get a little unwieldy at times. And you should always remember to make the auxiliary that you bring to the passive agree in tense with the original active voice sentence. See how I had to bring the passive voice auxiliary verbs in line with the original active voice tense in the above examples?
I will add that one of the problems with the passive voice is that it lends itself to “subject dropping”–that is, you can still have a correct sentence without a subject:
The passive voice is not recognized.
The ball was kicked.
The tennis match was won.
Blackjack is played in Las Vegas.
This can be a notorious way to get out of specifying things. A few of my students tried to use it on many occasions, only to get a big, red, “By whom?” or “By what?” on their paper, if specifying the subject was necessary. And trying to get out of specifying the subject when it was a part of the exercise was perhaps one of the stupidest things any student tried to pull in my class.
Former College-Level Grammar Instructor