Yep right but we are learning basics, and that would be nice to learn them correctly even if IRL it is correct/understandable. If we have to guess the context of dualingo also!! This also could be a question to yourself: Think, am I remembering everything? Or do I know everything ? About... I don't mind learning proper then colloquial thank you
English lesson: A word-for-word translation into English would be "Think, I everything know?" To the native English-speaker, this looks like a mess. To start out a sentence with the base verb followed by a comma could colloquially be interpreted as a command, but it's supposed to have a semicolon instead of a comma because "think" by itself is in the imperative, and, therefore, an independent clause. But in Russian, "Думаешь?" means "Do you think?", NOT "Think.". So after putting the object and verb in standard English order, we're left with "Do you think, (do I know everything / I know everything)?" It's easy to think that "я всё знаю" is the question because it's the correct way to say both "Do I know everything?" AND "I know everything." in Russian. But since "думаешь" came first, we can safely assume that the person being questioned is "you," and not "I". So we're left with "Do you think, I know everything?" The comma is necessary in Russian, but it would be incorrect in English because "I know everything" is the object of "think" (what "you" are thinking). So that's how we arrive at "Do you think I know everything?" Yes, I know, English is a logical, insane, stupid, sophisticated, simple, and complicated language. That's why I'm here learning alternatives.
I suppose it makes literal sense in a context where someone is talking to themselves, though in that context it doesn't make much practical sense (you would never say that to yourself, I guess).
In any case, the verb "to think" here is in the ты form (see https://en.wiktionary.org/wiki/%D0%B4%D1%83%D0%BC%D0%B0%D1%82%D1%8C#Russian), indicating that your version should be "You think, do I know everything?" which is quite Yoda-like and would feel more natural as "do you think I know everything?".
"You think i know everything" is not really a question in english. People talk like this, but it is not really considered proper english for the punctuation to be a question mark...so should it end with a period or should the sentence be changed to "DO you think i know everything"?
You think I know everything? As translated, in correct answer section is wrong. it should be advised as: You think, Do I Know everything? or as it is translated in above topic " "Думаешь, я всё знаю?" Translation: Do you think that I know everything? "please make a correction in reply answer. Thank you