"कोई आ रहा है।"

Translation: Someone is coming.

[phil.j.regan]

How do we distinguish between "no one" and "someone"?

[Zerenei]

कोई = someone, कोई नहीं / कोई भी नहीं = no one

[Brandishanti]

Thanks. And also what is the difference in meaning between koi nahi and koi bhi nahi?

[Rosh_win26]

Koi nahi is no one
koi bhi nahi is no one at all

[JeramyMill]

Whats the difference between anyone and someone?

[Rosh_win26]

As far as i know, there is no difference.