Because it is a universal language. English serves as the fourth most widely spoken language worldwide with over a billion speakers daily the language is primarily used for international affairs and social gatherings. Many countries are said to be fully developed because of it’s use of English language in interacting with tourists and local residents as well. It will not be hand on your part when you’re going to communicate with family,friends,work,colleagues. Improving your grammar will help you clearly understand the ideas, core values and even traditions of people you encounter from a different race culture or religion.