New knowledge and English English is the most popular language in the world. It is not the most speaking language in the world (I know it is Chinese), but the knowledge that there is English texts, videos, audios, etc is incredibly important. If you want to learn a new language the best educational resources are in English. If you want to learn a new technology the best resources are also in English. Even people who are the guru in some technology likely to have their lessons in English rather than in their native language. So if one wants to learn new things it's undoubtedly important to be able to understand English speech. If there is the necessity to share your knowledge you should speak English that way that people understand you and your ideas.