The conjunction "а" has both a contrastive meaning and a contradictive meaning. In its contrastive function, it is used to join two or more complete statements that are placed close together for contrasting effect. In this usage it is usually translated as "and", with the connotation "while, whereas".
I agree, and have reported it. I think I slightly prefer "but" in this example, but it wasn't accepted. (Or do I mean: "AND it wasn't accepted"? ;) )
You have a mistake in a sentence: ona uzhe doma. Translastion is "She is already AT HOME". We use: I go home but I am at home
Note in pye20, comment that the consonant is held longer for Anna too, so doubled consonants does make a difference in Russian.
I think that the dash is omitted with pronouns. But if it where for example "актёр" instead of "Ты", there would be a dash.
I used but instead of and, and it was marked wrong. Why do they use "a" for and instead of "и"?
[ а vs и ] ‧ In Russian, [ и ] is used to show similarity. ‧ [ а ] shows contrast ‧ examples: ‧ www.duolingo.com/skill/ru/Conjunctions/tips-and-notes ‧
Дом ‧ Home / House ‧ [ Noun ‧ place / environment ] ‧ => дом (здание / строение) ‧ classes.ru/grammar/32.kutuzov/4/4_02.htm ‧
До́-ма ‧ at home ‧ [ Adverb of place ‧ Where? ] ‧ classes.ru/grammar/32.kutuzov/4/4_02.htm ‧
До-мо́й ‧ homewards ‧ [ Adverb of motion ‧ To where? ] ‧ домой ‧ [ to go / to come / to be (back) home ] ‧ classes.ru/grammar/32.kutuzov/4/4_02.htm ‧