"Why do not you come here?" vs "Why do you not come here?"
I have two questions.
- What is the difference between "Why do not you come here?" and "Why do you not come here?"?
- Are both of "Why do not you come here?" and "Why do you not come here?" grammatically correct?
No, the order "Why do not...?" is no longer grammatical in contemporary English.
Regarding the "What's the difference?" question, if you correct the first sentence to "why don't you come here?", then the difference is:
"Why don't you come here?" is most often used as a suggestion. It is equivalent to saying "Please come here now."
Fred nervously took a seat on the other side of the room.
"Why don't you come here?" Beatrice purred, patting the loveseat beside her.
"Why do you not come here?" is a question seeking the reason why you refuse to be someplace.
"Let's go in here and get something to eat," said Don.
"No, not here. I never eat at this place anymore," said Bob.
"Oh? Why do you not come here?" asked Don.
The "Why don't you" form can be used equivalently to the "Why do you not" form; the emphasis used when asking will make clear which meaning is intended. (For the suggestion, the emphasis is on "here"; for the question, the stress is on "come" or possibly on "don't".)