"Excuse me, do you have a sister?"
Translation:Извини, у тебя есть сестра?
Извини, у вас есть сестра? was not accepted. I thought it should be and reported it, but now realize that I was wrong. Sure wish I could find and delete my report, because it wastes moderators time.
It took me a while to figure it out, but finally I found in a conjugation table that (ты) Извини/(вы) Извините are imperative forms of the verb извинить. Извини isn't just some sort of diminutive form of Извините.
That makes me wonder about Russian imperatives: It's "Excuse me!" (a command). We do the same thing in English, but it's a short-hand for the polite form stated in conditional tense, "would you excuse me?" Makes me wonder if there isn't a polite form - or if the Russian is taken as a polite form more than an imperative command.
Also, извинить listed in my conjugation table as the "Perfective Aspect" of a verb-pair. The "Imperfective Aspect" is извинять, which has a different set of spellings in the conjugation table which parallel each conjugation in the Perfective Aspect. The trick now is to figure out what "aspects" are.
Present tense conjugations all appear to be in Imperfective Aspect - there's no Perfective Aspect present tense listed in the conjugation tables.
Can't wait for this little mystery to be solved.
My attempt: "извините, у тебя есть севтра", which was marked incorrect and the correct answer was 'извини' Looking at other comments here, 'извините' и 'тебя' are both formal, so my combo feels like it should be right. (As oppposed to informal извини + ты). Any guidance will help me alot! Thanks!
Formal/informal conflict within your sentence. Choose either informal or formal and stick with it throughout your sentence. Извините is formal style. All variations of you must be formal after starting with that.
The actual grammar is a little more complicated than simple formal/informal but thinking of it that way will solve your problem for now.
Извини (меня - me (их - them)) vs извините (нас - us, её - her, его - him, меня - me(also!),их - them). Главное в другом, Извини - обращение к (приятелю) равному по рангу(или ниже, или просто хамство) человеку; Извините - культурное обращение к уважаемому (по любым причинам) собеседнику.
Since you haven't copied and pasted what your answer to the Duo example was, there is no possible way to answer your question with certainty. However, my guess is you made the common mistake of mixing formal and informal in your sentence.
The first word in the sentence is formal извините, so everything after that should be formal.
Marking an example wrong while providing the correct answer actually is teaching. Even more so when considerably more information specific to the issue is available by means of a keystroke. And not just specific to the issue but specific to the particular area of confusion for the student. Much if not most of the Duo teaching comes from the these comments pages.
However, I agree it is possible that translation exercises are not the best form of teaching for you to accomplish your goals within your comfort zone.