Translation:Do you know?
知道 can't be used for "understand". it's more like an identifying type of knowledge, like when talking about facts, such as "did you know he has a sister - 你知道他有妹妹吗？" rather than understanding concepts.
There is no difference in meaning, but I think 知 without being followed by 道 in Mandarin only exists in idioms (e.g. 不知好歹). In Cantonese both 知 and 知道 are allowed though.
I believe more vocabulary example should be provided in the tips. This would help us understand the different meanings of the character combinations.
Sort of... but I think (你)不知道(吗)? Would be more accurate for that. - 你 & 吗 could be omitted and "understood" in context
Do people also unnecessarily add this to the end of their sentences like in English and French?
Since 知 and 道 both mean "know", why do we need both of them? I have a feeling this will keep coming up where two characters are used for a word when they both seem to mean the same thing.
This seems grammatically wrong. Is this a normal question in Chinese? Do you know "what"? What exactly are you asking?
That may not be a very good translation, yet the Chinese sentence is absolutely a viable one.
You should not bully your younger brother. Do you understand?.
Have you heard about it? John has been fired!
No, I'm Chinese and when I'm asking someone if they know something I usually say "Do you know...........".
Do you know and do you know this is both the same. They also have the same meaning. Do uou know this must be accepted because they both are the same people.