Agreed. The neurological basis for the relationship between what English grammar calls subject and predicate is a really interesting subject, and verb voice is

Agreed. The neurological basis for the relationship between what English grammar calls subject and predicate is a really interesting subject, and verb voice is obviously very related. My background in all this comes from a few classes in Chinese linguistics. Chinese, like many East Asian languages, divides sentences into "topic" and "comment" rather than "subject" and "predicate," so that the topic can be what we would consider the verb's object even without the verb being explicitly marked as passive. Yet modern Mandarin does have something like the passive with the modifier "bei-" which, when put before a verb, indicates the passive. This has a somewhat literary or ironic tone and is almost always used for negative actions like "he was hit" or "she was criticized." My favorite usage: When the Chinese government blocks website in the name of "social harmony", you say the site "bei-harmony," or "been harmonized."