What are you reading?
It's an article about language. It talks about the idea of having a single global language.
It seems that English already is the main global language. Does the article suggest that there should be an artificial language like Esperanto as the world language.
Actually, it suggest English. The main argument is that English is already being studied as a second language in most countries-china, India, mexico, Nigeria, Pakistan, and japan. So beginning again with a language like Esperanto would be wasteful. The second argument is that English is used in modern technology far more that any other language. Most emails are sent in English and the vast majority of website use English.
Does the article say anything about other language? How will they survive in an English-speaking world?
The article points out that many languages have been lost and will be lost, but others will continue to be used for generation, even if English continues to be the dominant language.
Right. All the people who speak Chinese. Hindi, French and Spanish aren't suddenly going to stop using those languages.
Exactly. The article suggests that those languages will be used, but that they will only rarely be used in international communication between non-native speakers.