English-Speaking World
English is the most popular language in the world to learn right now. It is the lingua franca of international business and politics. When combining native and non-native speakers, it is probably the most commonly spoken language in the world with over a (whopping) billion people who have a basic or better level of proficiency. Over 375 million people speak English as their first language (third in rank of total native speakers after Chinese and Spanish), and it is the number one second language to learn. The majority of the content on the Internet is in English, making it indispensable for research. It is also very useful, some might say necessary, when traveling pretty much anywhere.