1) Russian language is the most widely spoken among Slavic languages. You should certainly learn it – there are about 300 million total speakers of Russian in the world.
Russian became one of the languages of world communication – a global language – as early as in the twentieth century. Today, there are less than ten global languages in the world. This means that the Russian language – just like English, French or German – is used for communication by a very large number of people around the globe. In addition, Russian is one of the official UN languages. Out of approximately 300 million people in the world who know Russian, 160 million people consider it to be their native language. The Russian language is ranked the fifth most prevalent language in the world.