Time to BLOW YOUR MIND

The only exception that English has with the word "do" that makes it kind of different from other languages is in sentences like, "do you know what this means?" In which case, it's just an additive verb to make the sentence full. "You know what this means?" doesn't make sense in all situations otherwise. lol

French: Know-you what this means?

Exactly what we do with Do.
"I know what this means" = "I do know what this means"
"Do-I know what this means?"

Not sure what you mean by "it doesn't make sense".