One high level way of analyzing a phrase centred around a verb is to break it down into the agent (actor performing the verb) and its patients (things acted upo

One high level way of analyzing a phrase centred around a verb is to break it down into the agent (actor performing the verb) and its patients (things acted upon). Most of the time in English, the actor corresponds with the subject of the sentence and the patient with the direct object. (I see the dog. Agent - I. Patient - the dog.) That's whre the active/passive terminology comes from. Is the agent present in the sentence? Is it in its usual position as the subject? Then it's active. The passive voice is when you de-promote an agent from its usual place. In English this transform is accomplished with the patient becoming the grammatical subject with to be as an auxiliary verb, and the agent is either deleted entirely or tacked on as an adverbial. "The dog was seen (by me)." IMO, the style guides are overly prescriptive about this. Sometimes de-emphasizing the agent is exactly what you want to do. After all, such style guides effectively insist that Ronald Reagan should have said "I made mistakes", not "mistakes were made". (As an interesting footnote, as far as I'm aware, every language has this form of transformation. It's in all tho Indo-European ones, as well as Chinese, and ancient Akkadian, amongst others I've read a bit about.)