[vitus]

I think it's a useful start, but I for one still prefer consulting a dictionary on the side (e.g. Whitaker's Words -- https://latin-words.com/) to make sure I get the nuances and make sure I parse the individual words correctly.

The first thing that stood out to me with the translation is that it goes word-by-word, and doesn't have any room for ambiguity.

For instance, in the first line, "profectus est" is the third-person singular perfect form of the deponent verb "proficiscor" based on context, but it could also be the perfect passive form of "proficio" (which my brain initially gravitated toward, as one of the many derivatives of "facio"). I'd be a bit worried about picking the wrong one if given the word out of context. Or even just picking the wrong translation for a word: for the second sentence, using the word-for-word translation, I might try for "He long was spent at Periander, king of the Corinthians" when "He long dwelled at the house of Periander, king of the Corinthians" would read more naturally, using different translations for "apud" and "versatus erat".

Further, if you don't treat these pairs as holistic verb forms, you get very confused by just reordering words: "Arion, after he is having traveled abroad, ..." vs "Arion, after he traveled abroad, ..." And, it can cause some issues with relative ordering of events (where it's common to move between verb tenses to indicate that some events happened further in the past -- pluperfect vs perfect especially).

And, if you treat "erat" as "was" all the time (as is the case with "versatus erat"), you'll interpret pluperfect (which implies finality) as imperfect.

Later in the first paragraph, I'd run into a little bit of trouble with the ablative absolute ("Ingentibus opibus ibi comparatis"): "Great wealth there acquired" would more literally be translated as "With great wealth having been acquired", or, taking some liberties with the translation, "After he acquired great wealth, ..."

Moving on to the second heading: yes, "ut" is most commonly used as part of a result or a purpose clause with the subjunctive, but a newer reader might not understand why we use the subjunctive here instead of the infinitive. The most literal translation might be "The sailors make a plan such that they might rob and kill that man", but yes, once you're more used to the language, you'd translate it simply as "The sailors make a plan to rob and kill him".

[randomcatuser]

Learned something new. It's incredible that you have this kind of detail... do you think there's a UX that can help readers learn more/explore this kind of ambiguity?

I think the interlinear is realy good at showing one translation (and isn't super distracting) -- do you imagine more like footnotes/etc type things?

[vitus]

I know various e-readers have the ability to look up unfamiliar words or phrases in a dictionary by tapping on them, so you can focus on only looking up things that you don't know, or look for another definition for some word if the definition you have doesn't quite fit. For instance, I would probably need to revisit my parse in that first sentence, "Arion, since he (or perhaps some unspecified deed? but why not the ablative absolute here?) was accomplished abroad, ..." using proficio as "has been accomplished" instead of proficiscor for "departed"); looking up profectus in a dictionary would yield the other base word.

I also wonder about jotting down translation notes while reading -- when seriously trying to translate a text, writing down notes in the margins or between lines (if there's appropriate spacing) helps a ton. At least until you're familiar with the grammar and the constructions, laboring through the translation is a huge help.

For someone like me who is reasonably familiar with the grammar, but might be rusty on the actual vocabulary (having last needed to use it in any semi-serious context more than a decade ago), I could see myself referring to the existing app's translation on occasion to give me some ideas regarding the actual words. But I don't know how helpful it is for someone newer to the language, who'd need more than just vocab.

Another commenter also mentions the possibility of pairing the Latin text with a well-established English translation. That might also be interesting; I could certainly muddle my way through a translation without knowing the grammar, but I would make plenty of mistakes if I didn't stop to think about cases and verb forms. What I think would help most is to perform a surface reading, followed by a refinement to make the text more idiomatic.

For instance, taking one of the sentences in the second paragraph: "Pecunia omni nautis oblata, vitam deprecatus est." My surface reading would look something like... "With all money offered to sailors, he begged his life." I might then refine that to "Having offered the sailors all of his money, he begged for his life."