**Having your day-to-day conversations in English is the best way to go, I would say. **
I think there is a feel to every language. I speak three languages which can be argued to be of different origins – Marathi and Hindi, and English. Marathi and Hindi are quite similar and have different sentence structures than English. I think one can understand and familiarise oneself with sentence structure most effectively by conversing in that language.
To familiarise yourself with English, you can start by reading a lot of English literature. This, of course, is assuming that you can read, understand and construct the most basic sentences (for instance, “I eat bread.”). As you progress, your ability to converse in English will get better, because you’ll learn the grammar and structure. Once your ability is strong enough, you’ll be able to construct sentences with ease. If you happen to read/construct an incorrect sentence, an inner voice will tell you that it just doesn’t feel right.
The other way to go, which is memorizing grammar rules (which are enormous in number), will not only disable you from conversing in English but will also not help you to develop a grasp of the language. This might be a shorter way out, but considering the long-term picture, wouldn’t be of much help (This has happened to me. I studied Sanskrit in my school for six years, and at the end, I couldn’t speak fluently in Sanskrit. The way they taught the language was exactly as is mentioned here – they made us memorize rules).