Yes, with the one addition that things that get pluralized with -Du' also get lumped in under bIH. Have you checked out the Tips & Notes? Duolingo has hidden the Tips & Notes I want to make sure you know about them and where to find them. If you have not been reading the Tips & Notes, I would like to ask that you review those.
If you are doing the course on iOS or Android, you cannot currently access the Tips & Notes through the app. To access the Tips & Notes, you will have to access the course using a web browser at https://www.duolingo.com/. You can still do it on your mobile device, but you will have to use the web browser instead of the app (or you can do it from a computer). When you click on a Skill, it will expand to reveal a Start button and a Tips button.
If you click on the Tips button it will reveal the Tips & Notes and give you a detailed explanation of the grammar that is introduced in that Skill. If you have questions after reading the Tips & Notes for any Skills, we are happy to answer your questions, but many of your questions will probably already be answered in the Tips & Notes.
Please forgive our continual reminders. I don't really pay attention to who is making a comment and even when I do notice that it's the same person, I sometimes pretend that it is a brand new person. That way, if a brand new beginner comes across the answer, they get maximum information. I think you will find the Tips & Notes to be very helpful, but please don't take the repitition as chastisement. We are just repetitive like that so that complete information is available on every post. Which reminds me I should edit my above post to include the actual instructions in case this thread is the first time someone sees mention of them.
I can see what you are saying, but why would "beings capable of language" be mistaken for rocks. I'm not asking for a creative answer, just pointing out that it would take a rare and unusual circumstance. These is an actual limit to the number of translations allowed, and additionally, if we start imagining wild contexts it's easy for the translations to get to loose and not be helpful in teaching the normal limits of the language. Rocks are not beings capable of language. You are mistaking something for rocks and have to point out that they are not actually rocks. bIH seems like the right pronoun.