what are the best ways to improve english in all aspects in very less time?

Immerse yourself. Speak, read and write only English for a while. Read newspapers and magazines in English. Meet and talk with English speaking friends.

I taught myself English out of comic books. ~

Be aware that learning a language to the point where you are fairly fluent usually takes about 2,000 hours of immersion in it.

Talent obviously matters. Recently a guy with an incredible memory learned Icelandic, a very tough language, well enough in 1 week! that he was able to go on a TV interview and understood and answered all questions in that language.

it all depends on basic concepts u have ,first of all read a good english grammer book like wren and martin,then u should have a good command over voucabloury,at least 2000 words u should know.read english news paper daily.try to talk in english with others.learn the word meaning from dictionary.

besides reading writing and speaking in eng.

this book could be a great help : Word Power Made Easy

by Norman Lewis.