I don't think Chinese will replace English as the most spoken language all over the world. There are some reasons: 1.The popularisation of English is certainly one of the most important part of the globalisation. Its status will be solid in at least 20 years; 2.English is in general easier to learn, compared with Chinese. I mean IN GENERAL!(cause some have opposite ideas to it)In a way, it means that it's more efficient to become in proficiency in English; 3.English shares a similar alphabet with a lot of languages, while Chinese uses an unique writing system. Although Englis has been through the Vowel Shift, people can work with reading and pronunciating together while Chinese learners have to deal with characters and their pronunciations separately. They are also other reasons supporting it. Nevertheless, it's indisputable that Chinese becomes a trend for those who are ready to learn a foreign language.