Dear "Anonymous,"
You can certainly learn to speak and write in English, but you will have to make serious effort for the same. You can learn the language by reading English newspapers (e.g., The Times of India), good magazines (e.g., Reader's Digest), listening to English news bulletins and discussion programmes on TV. You have to be patient and while reading be careful to note the sentence formation, choice of words, punctuation, grammar, etc. Consult a good dictionary (e.g., Chambers Dictionary) whenever necessary. It will take time, but you will certainly succeed.
Best wishes.
A.K. Gupta