This relates to my long standing war with grammar. I am, at best, poor at spotting these types of problems. I have to use a dictionary or do research on the web to define "passive voice". Even then, the definition is a just a string of words to me. I recognize each word, I can tell the definition is well formed and clear, I get the basic concept, but a clear grasp of the details never crosses into into my consciousness.
Mind you, I am not a stupid man. I am a computer programmer. I read and understand highly technical books and articles loaded with technical jargon on a regular basis. Nevertheless, I don't really understand something like:
form of "to be" + past participle = passive voice
Here's what I do get: Does a sentence sound awkward and ill-formed or not?
For example, "Why was the road crossed by the chicken?" sounds to my ears like an awkward phrase. It is an unnatural way to ask the question. It has the same content as "Why did the chicken cross the road?" which is clear and more natural. I know, intellectually, the awkward sound of the first version comes from the fact it is in passive voice. I know this because the web site I copied it from says so. Had the website not explained this I would never have been able to identify the problem, I would have just known there was a problem.
Listening to recording of the writers group meeting, I realized that the passive voice creeps into my writing as a writing crutch. The passive voice is not grammatically incorrect, but it does detract from the content of the writing. Often, the passive voice is a lazy way to say something.
As I write, particularly on my early drafts, I tend to focus first on plot and character. Style is a matter of polishing the final work. Rewording a sentence to avoid the passive voice takes more time and effort. Rather than take that time, make that effort, I unconsciously lean on the passive voice over and over. Over time, using this writing crutch weakens my characters and erodes the story.
This is not the first time I found myself relying upon a writing crutch. The use of the "ly" words is also a crutch. (Angrily, sleepily, madly, stoically, happily, sadly, etc....) These words are a lazy way to establish a mood or emotion. Often they can be left out without changing the content of a sentence, letting the context establish mood and emotion. Sometimes descriptions are needed instead. For example, "What do you want," she asked angrily. versus, "What do you want?" she asked, her hand clenched in a fist.
When I discovered I had an problem with overusing and abusing "ly" words I declared war upon them. I began scouring my writing for every instance and replaced as many as possible. Sometimes I couldn't, but I did manage to reduce the problem to an acceptable level. Now I try to avoid "ly" words in the first draft, which makes my editing process shorter and simpler.
With regards to the passive voice problem, I am now declaring war on the "to be" verbs. (Is, are, am, was, were, has been, have been, had been, will be, will have been, being.) This lets me focus on a well-defined set of words that are often the hallmark of the passive voice. When I find a sentence with one of these words I will examine it to see if I can rewrite it without a "to be" verb. Often I won't be able to, but just as often I will discover a more natural, less awkward way of expressing the same idea. At the very least, I believe the practice will make me a better writer.
I admit, this approach is a gimmick. It isn't a true substitute for understanding grammar. But, since I don't really understand grammar, I have to rely on gimmicks to help me improve my skills. It may not be the best approach, but it is a technique that has worked well for me so far.