THIS and THAT
Re Insight posted by Christian: I was taught to use "dieser" in most cases, except when comparing things: "Dieses Auto ist schwarz aber jenes Auto ist blau". Duolingo seems to translate "Das ist - - " mostly as "This is - - ", rather than "That is - - ". I haven't yet seen Dulingo introduce "Dies ist - - ". The English sense of it is generally: "this" is for things close to hand and "that" is for things more remote.
Maybe it was true a year ago that "Das ist --" was translated mostly as "This is --." I joined a month ago and now "Das ist --" is only being translated as "That is -- " to the point where "This is --" gets marked incorrect and a heart is taken away (sometimes). It might be the case that the upgrade went overboard. I find it odd that almost all demonstrative statements in English start with "That is --" regardless how simple the statement is.