How to display different input while you are typing in c#?

Question

For example, i am typing this in a textbox "Hello world"
But i want it to be displayed as "You are now typing" while i am typing it per character.
Like, i type "H" it will be displayed as "Y". Then i will type again " e" and will be displayed as "o" and so on. Is it possible?
Its like password masking but not using "*" but a sentence instead.
Thank you.

Answer 1

Use the description box, because the question is ambiguous.

Answer 2

I have already editted it, thank you for advising

Answer 3

Try graphing programming and generating cyphers.