I learn my English from a Western guy and my English is much better now. And, he told me that there is no Business English. Only ENGLISH. If you can communicate in the office, you can communicate outside the office too. If you can communicate outside the office, you can communicate in the office. And he is absolutely right! The only way is find a way to improve your English. And there is no such phrase "too late to learn".
Referring to your case, if you wanna know how to pronounce the words, you need to learn pronouciation. It is not difficult at all. There are some books in Page One that can help you out.