The population of India is similarly statistically divided into speakers of Hindi, Tamil, Bengali, and so on. But, as an Indian, I can vouch for the fact that not only are a large percentage of these so-called non-English speakers very fluent in English, but English often functions as the preferred mode of communication between speakers of different Indian languages or dialects, just as Common does in a D&D world. Heck, English is one of India's two national languages, for exactly the above reason.