Interesting. My Latin is terribly rusty but I would have translated the English sentence into Latin by using a construction with "ut". I see after doing some reading that the accusative+infinitive construction works just as well here. I'm so glad this course is giving me the opportunity to brush up on these things.
This is really interesting!! I always thought English was "odd" in the sense that it used this construction with the infinitive, since in Spanish, Catalan, and other romance languages you'd say something like "I want that the river flows rapidly". Now I wonder why these languages translate these phrases in the way that they do, instead of the Latin way...
In fact, I opened this page for the same reason. In Romance languages this utterance would trigger the subjunctive. I thought it was odd that it didn't in their parent language, and odd also because it seems Latin usually has more complicated grammar, not simpler!
What does "flow the river" mean?
Since fluere (to flow) is a verb of motion, and intransitive, it's not an action that someone can "do to" someone or something else.
In this sentence (strange as it is), the only thing capable of "flowing" is flūmen , the river.
"You want the river to flow rapidly," so maybe you don't dam it up (?).
By contrast, ascendere (to climb) is a transitive action, so "climbing" is something that "you" (the subject of vīs = you want) can do to the tree.
I had this answer with an audio prompt and it was a little muffled, and the fluere and vis run together (I understand that that happens in normal speech, but it confused me on the parsing) - the 'play slowly' does not work, it replays at the same speed. I could not make sense of it, in part because of the audio and in part because ... well, it's just a weird sentence.