That might be a cultural thing. Perhaps teachers and students are able to establish a close friendship, especially in small towns, where everyone knows each other, and one another's residency as well. Just a thought... Or perhaps these are private students and the teacher gives them lessons at their home.
That may be beyond their scope (or indeed on the other hand, maybe that's exactly what they intend to do). But in the meantime, until they do, or do not, get that coded, I recommend OpenRussian.org (see here for the entire conjugation of the verb, including stress marks) for conjugations. I always keep this or Wiktionary open when I'm on Duolingo - helps a heck of a lot, and my scattered brain always wants to look up all sorts of definitions to words completely unrelated to the actual assignment at hand. Hope it helps you, too.
I don’t know the history of why we do this in English, but when we ask a question, we use helping verbs - one of these helping verbs is a form of do/does. The helping verb is generally placed before the noun or pronoun. The verb it helps then takes a static form (the first or second person conjugation) no matter the subject. The conjugation falls on do/does.
- Do you like to read books?
- I like to read books.
- Do comes before you in this question.
- Does Max think this is a fun game?
- Max thinks this is the best game ever.
- Does comes before Max in this question; “Max thinks,” but “Does Max think?” - in a question, “do” is conjugated, not “think.”
- Do Sami and Phil want to join us?
- Yes, they want to join us.
- Do comes before Sami and Phil; “do” is conjugated, not “want.”
- Does she believe that all tornados form from the ground up?
- Yes, she believes that is how tornadogenesis occurs.
- Does comes before she; “do” is conjugated, not “believe.”
This usage of do as a helping verb in English is different from usage which corresponds to делать.