Why you no come?
Why you no talk English?
Why you no have a girlfriend?
What kind of English are these sentences? Are these types of sentences grammatically correct?
It's difficult to tell what is being asked here. This question is ambiguous, vague, incomplete, overly broad, or rhetorical and cannot be reasonably answered in its current form. For help clarifying this question so that it can be reopened, see the FAQ.
I guess you are talking about the Y U NO guy.
So basically, no, they are not proper grammar, but they work great in situations like these, because they bring people's attention. Like they brought yours :)
None of them is grammatically correct. They should be:
I offer past and present tense choices because there's no context to tell me whether they refer to the present or the past.
Also, there is never a space between the last word in a question and the question mark.
The kind of English you ask about is possibly either a pidgin or a stereotype of how people who speak pidgin English sound. This is common in old "cowboy and Indian" movies about the American west and other English-language movies with characters who aren't fluent English speakers, especially characters who might live in jungles, in grass huts, or in caves.
Simply put, English requires the helping verb "do" in each of these cases. It is somewhat idiosyncratic, however, enough to the point where it becomes a useful marker of the knowledge of the language, at least insofar as popular movies are concerned...