I know that while, like after, before, when, as soon as introduce time clauses, which require the present simple:
I'll keep you company while you wait.
But so many of the students have used the present continuous on the quiz I gave them because this is taking place at the moment of speaking.
I'll keep you company while you're waiting.
I've checked online and have seen both used. I'm certain that the present simple is the correct answer according to standard grammar rules. And that's what I would say and write. But the present continuous doesn't sound so bad to me, now that I see it written.
I'd appreciate other opinions on this.
Best Answer
Both versions are grammatical and standard English.
Here's some related info from CGEL, on their subsection on "(d) Duration", pages 165-6:
Note that CGEL is the 2002 reference grammar by Huddleston and Pullum (et al.), The Cambridge Grammar of the English Language.