So, I've been working on a conlang for quite some time now, and I've devised a gramattical "alignment" of sorts, the likes of which I have not seen anywhere. I have grown to give it the name "noun-dependent valency", or, slightly more narcissistically, the "Meonic Alignment"
Basically, the idea is that agency can be given to any noun phrase regardless of its actual case role. The agent is always the first noun phrase after the verb.
For example, we have the sentence "J'toka al takep", which means "We're visiting the lake". J'toka "to visit" has no marking, taking on a present continuous tense. "al", "we", is the subject, so it takes no marking as well. "kep" takes the accusative prefix "ta". The first noun phrase is the semantic agent, as well as the grammatical subject, so we get an active voice. Easy.
However, if we were to swap the second and third word, we would get "J'toka takep al". The grammatical object, is now the semantic agent, so we get a passive voice! The sentence now means "it is the lake that we're visiting", or simply "The lake is being visited by us", the distinction only made by swapping the words around - no verb modification required!
This system can be used in a lot more ways than you think. For example, the language has no verb for "to have". Instead, you promote the phrase "of x" to the agent. As an example: "O ś'rel tola" means "The house is mine" (literally "Is house of-me"). But, if we were to shift the ourselves to agent position, we get the sentence "O tola ś'rel", which literally means something like "It is of me that the house is", or simply "I own the house"!
The examples are countless. By agent-ifying the noun phrase "because of x", we get a meaning akin to a causative ("it is because of x that this is happening"). By rearranging the sentence "We are inside the house" to make "house" the agent, the sentence takes on a new meaning! "Being the thing we're inside of" is now a conscious (?) action, which the house is performing!
I'm really proud of this system, but, again, I have seen no language, real or not, utilising it. Could someone help me put a label on this? Any feedback is greatly appreciated.