It's very hard to say whether China will become the largest economy or not because it's very competitive country and it's at the right direction right now but so competitive is the United States. At the moment I think that China does everything better and they are doing more things behind the scenes. For example, in my country, soon Chinese will be a mandatory language at schools and consider that our language is far from Chinese. At the moment, Russian and English are mandatory languages at school and as a third language, we learn basics of French or German but now Chinese will be taught at school along with English, Russian and Chinese. Our current government tries to distance from the US and EU, they want to stick with Russia and China. I personally dislike this idea for so many reasons, including historic experiences, that it will take me a lot of time to write down all of them. Btw if China is doing this with us, they'll do it with other countries but I don't know how people will learn Chinese because our languages are extremely different and it's almost impossible to learn Chinese if you don't dedicate your life to this language.