Duolingo has a Latin course.

Duolingo Latin is not useful as your only course. I would say it’s not useful at all, except perhaps if your normal Latin class is on break and you want something, anything at all, to jog your memory a bit.

On one hand, it is really short. There are very few words assembled into very few phrases, and they are not even particularly popular words. (New Latin for “New York”? I mean, I guess, but was that really the best you could do?..)

On the other hand, for how short it is, it confronts you with quite a bit of grammar. As is customary for Duolingo, you’ll have to infer that grammar from the examples—except, per the previous point, you won’t get nearly enough examples. (It’s cute that some usages of the Latin verb “studeo” correspond to the English verb “study”, but the Latin one governs an unusual case, which depending on declension looks exactly like one of the other cases, so perhaps having it be one of the first verbs is unwise, especially when a lot of your target audience ostensibly has no concept of “govern”, “case”, or “declension”.)

On the gripping hand, because of how short it is, there is a lot of grammar that it does not even hint at. Including parts that any classical text will hit you in the face with within the first paragraph, and that will completely befuddle you unless you’re aware of them. (Like the quaint custom of plopping the preposition in the middle of its complement, as in “qua de causa” lit. “which for reason” i.e. “for which reason” i.e. “therefore”, or for that matter “magna cum laude” lit. “great with praise” i.e. “with great praise”.)

By comparison, Ørberg excels at this to a downright supernatural extent. It’s like La Disparition except instead of writing a (pretty natural-sounding) novel without using the most popular letter of the language he wrote a third of a (pretty natural-sounding) textbook without using the most popular category of nouns and adjectives in the language, and his version is actually useful. And it’s like this for any grammar concept he wants to defer. His way does take quite a bit of time, though, I’ll give you that.

Duolingo simply does not work for actually learning a language. It's better to use something where you practice immersion learning, preferably with other people and there are apps for this online too.

After trying Duolingo a bit myself and seeing my family members try it, I've become convinced that Duolingo is worse than doing nothing, because it does a much better job of convincing you that you're learning than it does actually teaching you.

Do avoid.[1]

1: https://latin.stackexchange.com/questions/11413/is-duolingo-...

Duolingo has a tenth of a Latin course.

Source: I did the whole thing before I learned Latin from a different course. Duolingo's is unfinished.