Chander Pratap

I assume that you are talking about communication English here.
It's hard to communicate with friends who don't prefer to communicate in English so I would suggest going with the flow with friends. (not hard and fast rule).
Read.Read.Read.- Read a lot in English. Novels, magazines, in fact, anything even if its rubbish just read and marvel the words which fascinate you.
Watch movies in English (subtitles for beginners) and series. There are series which not only teaches spoken English but motivates you too. Ex- Naruto (cartoon).
Use, improvise, the sentence, words you find in those movies, books, series. Imagine the conversation in these scenes be it a movie, novel etc. and replace yourself and talk.
You will make a lot of mistakes. It's okay, and this will show you are improving.
 Keep practising and don't stop reading books ever.
Good luck!

As you have asked for spoken english first and most important thing is "SPOKEN". Yes whatever you read, see people speaking, write or communicate you need to speak that, visualise that in English. 

One of my favourite is I talk to myself while jogging, travelling or any free time I get. And most of time I talk in english. This has helped me a lot as I can edit many things that can be spoken in front of others. Not only this you can think of different words that can replace one word. 

Apart from this Novels, English movies, series has helped a lot.

Take what is best for you from my experience. 

Last Spoken english gets better and better over a period of time. 

Best example is u itself walking/jumping/running etc. First law "u will either be standing or sitting unless u exert some force to move Ur own body that energy u get from food(calories) similarly to stop from running. Similarly for second law " a fat person needs more energy to move dn a thin person (u might have seen fat person having difficulty to stand up) ie F=m*a." Third law "while running u push ground/earth with Ur feet and the earth exerts the same force on Ur foot and hence u run/walk. While jumping the more u push the ground downwards the high u jump. That's why generally u bend down the knee to apply more force on ground to jump higher"