Found in 2 comments on Hacker News
Jtsummers · 2021-04-02 · Original thread
Sort of. I just pulled up that book on Amazon. Check out the "look inside". The first chapter reads as an advanced version of "See Spot. See Spot run. Run Spot run!". Vocabulary is getting introduced slowly and as it builds up there is explanatory text or elaborations (in the prose or in the margins). A description of the language is being presented within the language, which Rosetta Stone doesn't totally get to. Rosetta Stone presents more and more examples with, at times, markings to help illustrate what they're getting at (-ar verbs get conjugated with -o, -as, -a, -amos, -an) but it seems this Latin book (I've exhausted my page views so can't see more sections) actually has a description of Latin in Latin, not just more words/phrases presented individually. (TBF, I never completed a Rosetta Stone course so maybe they get closer to this eventually, but that's not my impression.)

There's a very good book for Latin that uses that trick.

Goes from zero to extremely complex Latin. Whole book is in Latin, no translations.

The only requirement is knowledge of orthographic alphabet and how each sound is produced. Latin, fortunately, has very simple sounds compared to English or Swedish.

It took me about 2 years to go through both parts and I was amazed at how easy the journey was. Could speak and write Latin fluently without issues.

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