Your question is like the question 'How can I get slim and thin if I pig out a lot every day?'. There can be other variations of your question - How can I swim without swimming? How can I breathe without breathing? How can I drink without drinking? How can I paint without painting? How can I learn without learning?
The most easy, funny and amusing way is through listening to music! it is my personal experience actually, I have learned "and still learning" English through music. You can gain vocabulary by translating the new words you hear them in the song you are listening to and write it down in your notebook.
That was my vision, hope you all the best :)
dont learn any thing, you will learn nothing.Then you will learn something that is called learning
Some famous people CLAIM (we do not know if it is true or not) that they learned English just by watching American movies or TV shows.
Some people DO have an ear for languages. (That is, they have an ability to learn languages fast.)
I have just read about a young man who speaks American English very well, even though he did not go to school in his own country (he was too poor). He CLAIMS that he learned it by just watching American movies.
If you do not wish to spend time studying grammar, then maybe you can try that approach: Forget about grammar and just spend hours every day watching American movies and TV shows. Maybe in six months or a year, you will find that you not only understand what the actors are saying, but maybe you will also be able to speak English -- especially if you have an opportunity to practice with native speakers.
Get yourself English-speaking friends:) Preferably people who share the same interests or hobbies.