"La besto trinkas akvon."

That's interesting, I haven't thought of it that way. How I remember it is, besto=best friend, an animal can be a person's best friend. Similar to, "a dog is a man's best friend." It may sound complicated, but it works for me haha.

It could be just you, but maybe not. My sense, though, is that typo forgiveness is not something that the individual courses have control over. It's part of the behind-the-scenes workings of the Duolingo system, so I would expect it to be equally forgiving in all courses. I also know that the course authors occasionally add common typos as correct answers to reduce frustration.

The question came up about the difference between "beast" and "besto." See my longer comment in this thread.