Should Понимаете ли вы / Понимаеш ли ты also be accepted as answers?
I consider that yes. Have you reported? But pay attention, it must be Понимаешь :)
You're right, понимаешь. I tend to forget that final ь.
How do I report it now? Once I've left the question I don't seem to have the option to report anymore.
Oh, you should have reported while you were on that question. It's okay, others may see this discussion and report. :)
OK, I wasn't confident enough to report it without asking first and I didn't realize I wouldn't be able to report later. Should I start reporting even if I'm not absolutely sure?
Well, you can still report, and the contributors will decide themselves to consider your report or not, and they will also answer your questions, or tell you why your report is incorrect. :)
A general hint to consider. Понимаете is only acceptable when you use informal ты (Bы) which may be why your answer was incorrect (If you say ты Понимаете)
When you shoul use этот and when you should use эту
Этот is the masculine nominative form, эту the feminine accusative form.
"Ты эту книгу понимаешь?" Why it is wrong?
At this point I'm a bit confused; when are you supposed to use вы and when ты?
"Вы" is plural, and also is used as a polite singular form. "Ты" is informal singular, used with close friends and relations. They correspond exactly to German "sie" and "du".
Ok, that makes more sense now. Thanks for answering!
Is there a way to tell if the sentence is polite or informal? I was told I should've used ты even though it didn't mark it wrong?
What's the difference between книга and книжка?
From what I can find, книжку either means a book or a ruminant's second stomach, called a psalterium in English.