Katalagon, thanks for the Spanish. A good and natural example of subject-verb inversion in the text is:
un repecho que > hacía el camino
“a steep slope that the road made”
I have recently been obsessing about overall word order in Latin and Greek. After considering the initial question further and re-reading on my own some of Devine and Stephens’ Pragmatics for Latin, I want to amend some of what I said above and explain my understanding at length.
A pre-posed destination phrase equivalent to ad regia is absolutely possible in English, Spanish, and other SOV languages, however, I think the destination needs to be highly topical and generally old information.
For instance, I think it would be grammatical, but oddly abrupt to say:
()In ancient times to a/the royal residence came a farmer.
()En la antigüedad a una/la residencia real vino un agrícola.
But it would be fine to say:
Once upon a time there was a royal residence, and to that royal residence came a farmer.
Érase una vez una residencia real y a esta residencia real vino un agrícola.
(*Erātur ūnā vice ūna domus rēgia et ad istam domum rēgiam vēnit ūnus agricola.)
For similar reasons, I think it is probably odd in Latin to say something like:
(*)Ōlim ad rēgiam vēnit agricola….
Nevertheless, I think the pragmatics indicate a presentative sentence to introduce the farmer as a new character in the story.
As for the position of the subject, it is usually last in such thetic sentences, and presentational sentences are just one type of such sentences. In nomal sentences, there is usually a notional topic about which something is predicated. The sentence has two parts. In thetic sentences, there is merely a single event description, with any entities mentioned being viewed as part of the event itself. The sentence has only one part.
Another way to look at presentational (and existential) sentences is that most sentences go from an entity to a separate event or description about that entity, but presentational sentences go from an event to an entity that emerges from the event.
Thetic sentences demote participants in an event from being something about which there is a predication to mere details of a higher-order predication. Such sentences are like predications of unspoken assumptions like: “What is the next event, a relevant case, an independent justification, a resulting situation, a separate cause, etc.” They present a situation as a whole that can supplement or interrupt an ongoing narrative or exposition.
“Exeunt omnēs” (Everyone leaves) used to be a frequent stage direction in written plays to explain what situation you will see at the close of the play.
“Delenda est Carthagō” (Carthage must be destroyed) sets forth the situation claimed to face Rome at that point. It focuses more on what the situation is than on what should happen to Carthage.
“Gaudeāmus igitur iuvenēs dum sumus” (let’s party
while we are young) sets forth a situation to be embraced at graduation from university.
Here are some contrived, contrasting examples:
Senātōrēs Caesarem occidērunt.
This tends to mean: “what the senators did is kill Caesar.”
Caesarem senātōrēs occidērunt.
This tends to mean: “what happened to Caesar is that the senators killed him.” “Senātōrēs” remains the grammatical subject, even though “in the middle; but “Caesarem” is the actual topic of the larger predication.
However,
Occidērunt Caesarem senātōrēs
Tends to mean: “What happened (as the next event)/(as a result of the previous event)/(as a good case example of appropriate events) was the killing of Caesar by the senators.” The sentence does not aim to answer the questions “What did the senators do?” or “What happened to Caesar?” It just describes an isolated event from an objective viewpoint.
It is also possible for an object to follow the subject, but I believe this is a marked structure. The subject seems usually to appear last in the neutral order of most thetic sentences (other than imperatives), perhaps to indicate contrast, focus, or a mere tail clarification of what the verb refers to. Here are some authentic examples of the marked order from Devine and Stephens’ book:
Transfigitur scutum > Pulloni > et verutum in balteo defigitur. Avertit hic casus > vaginam> … Succurrit inimicus illi Vorenus (BG 5.44).
Pullo got his shield pierced and a spear was lodged in his baldric. This accident shifted his scabbard… His rival Vorenus ran up to help him (BG 5.44).
All these clauses portray a series of events from an objective viewpoint, which licenses the three initial verbs. (By the way, having “dēfigitur” sentence final, rather than initial, is actually quite usual for conjoined thetic clauses.) This textual strategy is good for narrating rapid fire changes in a scene. The lack of topics or sentence connectors gives the impression of watching events unfold in real time.
In the first sentence, although “Pullonī” is syntactically a dative object, it serves pragmatically as the subject at the event level and so is sentence final, leaving the grammatical subject “in the middle.” In the second sentence, the event is supposed to focus on the change in the scabbard, and so “vagīnam” is sentence final, again leaving the subject “in the middle.”
If the first sentence read “transfigitur Pullōnī scūtum,” we would be left picturing the shield, rather than the strong image of Pullo in peril. Similarly, if it said “āvertit vagīnam hic cāsus,” we are left with a mental image only of the action and not the resulting awkward positioning of the scabbard.
Here is another example of the marked order I just ran across in Livy’s introduction to his history of Rome:
[7]datur haec venia antiquitati, ut miscendo humana divinis primordia urbium augtstiora faciat;
(You see,) Antiquity is given this indulgence, that by intermingling the human with the divine, the origin of city states is made more majestic.
The initial verb interrupts a declaration about not criticizing the historical legends of the poets in order to signal that it spells out a condition that justifies this omission. The grammatical subject, “venia,” is not clause final because the word “antiquitāte” is the focus, as a contrast with historians whose task it is to seek truth, rather than legends.
In summary, a subject typically ends up in the middle of a sentence because it is pushed there by a word that does something subjects generally do and/or the subject is not acting pragmatically as a subject.