Translation:One cannot force a horse to jump.
it's an expression: You can lead a horse to water, but you can't make it drink. Meaning you can offer education, say, but you can't make people take advantage of it. .... Asked to use "horticulture" in a sentence, Dorothy Parker said, "You can lead a whore to culture, but you can't make her think."
I think EN218 was asking whether Duolingo's Norwegian sentence "Man kan ikke tvinge en hest til å hoppe." was a random weird sentence or an actual Norwegian saying. Is it actually the Norwegian equivalent of the American English saying, "You can lead a horse to water, but you can't make it drink."
You can certainly try to teach a horse to jump and to an extent, force one to (up... to a point. Maybe 2 feet/.6 m), but if a horse really doesn't want to jump, it really isn't worth the bother. Find the horse another job, and find yourself a horse that likes to jump. Because that's much more fun for everyone... (Yes, I have a riding lesson tomorrow ;-)
Just ask yourself whether 'til' and 'for' replace the phrase 'in order to...' rather than it simply being the infinitive or bare infinitive after an auxiliary verb.
Han liker å arbeide (he likes to work) = infinitive. Han vil arbeide (he will/wants to work) = bare infinitive after auxiliary verb. Han reise med bil for å spare penger (he travels by car to save money) = two verbs joined by 'in order to...'.
I hope that helps.