Question

You notice that your friend has a habit of littering on the street. You want to politely tell
her that such behaviour is unacceptable. You may also mention the swach bharat
abhiyaan campaign.

Answer 1

Good question.

'' Laaton ke bhoot baton se nahi mante '' - A known hindi proverb.
So as an amiable friend, you go to his/her house,litter it like a dumpyard and come back home merrily without his/her knowing.Then,make sure your friend comes to know that the menace creator was you.
I am sure,she/he will understand the bad demeanor he/she was exhibiting.

Cheers!