You can learn *some* English in one day. :)

I am English, I live in England, I teach English... and I am still learning! There is always more to learn about any language, not just English!

If you are a genius, you definitely can.

What you meant to write Osama was, "Can I learn English in one day?" OR "I can learn English in one day." Which did you mean?

You need to watch this video 'The Boy With The Incredible Brain' from the BBC: https://www.youtube.com/watch?v=z22H89rIMHk ...at 41:41 he is challenged to learn Icelandic in 1 week. Cheers...