According to many sources, including this helpful one from China, many of the world's languages are disappearing. There are mixed feelings about this, with some applauding the increased interoperability of world communications, and others lamenting the permenant loss of the history and culture that the now dead languages represent.
Almost all the dying languages are obscure village languages, dumped in favor of more business-present ones. It's easier to get a job if you can advertise your expertise in, say, Spanish over, say, Nahautl. (Nahautl is the native language of the Aztecs. It still exists, but is seriously being displaced in favor of Spanish.) Also, the internationally favored languages have greater cultural impact. America's endless supply of movies gives English an intense push worldwide. English is also preferred in India, which has an amazing 300 languages. English is preferred in India for two reasons. One being that it isn't really anybody's native language, so everyone is equally inconvinienced by learning it. The other being that the previous British domination of India gave everyone an equal chance to learn it. Many of India's 300 languages are amoung the endangered, although I definitely see Hindi, Gujarati, and Bengali surviving.
Although the Chinese source proclaimed all Chinese languages to be doomed, I must disagree. Two Chinese languages, Mandarin and Cantonese, will definitely survive. Yes, English is favored in China for the business presence, the extensive Internet presence, the movie presence, and the fact that it is the official air-traffic language by international fiat. However, those two languages have so many speakers that it would actually serve me, in America, good enough reason to learn them.
Here's my list of top twenty languages that I believe will survive at least another thousand years, making them effectively immortal, and why:
English is the native language of America, the UK, Canada, and Australia. All of these countries enjoy massive international prestige. The culture of these four nations is also highly valued worldwide, especially due to America's export of movies, music, and culture in general. Much of the Internet is also in English. In addition to all of this, English is favored in international business, and like I mentioned, English is the language of air-traffic control by international fiat.
English is quite famous for being flexible, and quite willing to absorb words from other languages.
2. Mandarin Chinese
Known as "Putonghua" internally, this Chinese language is the native language of northern China, and is the primary government language in China. It has 500 million native speakers and is well known by a number of other Chinese speakers. Anyone wanting to do business in China had better know it.
3. Cantonese Chinese
This Chinese language developed in southern coastal China. I'm classifying it as a language because it's more different from Mandarin than Spanish is from French. Yes, they use the same writing system, and quite a few phrases are quite similar. Yes, quite a bit of Chinese thought classifies it as a dialect of Mandarin. It's spoken in Hong Kong, which has an immense economy, and 105 million people speak it. Again, anyone wanting to do business in China had better know it.
While Japanese is only natively spoken in Japan itself, Japan's immense export of culture has taught it to nerds worldwide. Japan also has a very large economy. Very large indeed.
The Hispanosphere stretches straight from the tip of south America all the way up into the Mexican border with the United States. Meaning, almost all of the South American continent's nations use Spanish as their native language, as well as the Central American region, and southern North America. In addition, a large number of Spanish speakers desire to move to the United States, so any American in the southwestern region should learn Spanish as well.
French used to be the universal language of diplomacy and trade. The term "lingua franca" literally means "French language." Then, much to the fury of the French, it fell out of favor for some reason. It is still quite well known in any region that France ever had anything to do with. This includes enormous swaths of northern Africa, southeastern Asia, eastern Canada, and the middle east. French also has a large cultural prestige worldwide.
Spoken mostly in Germany, Austria, and Switzerland, it would be a wise language for an international businessperson to learn. The German economy is enormous. German also has some cutural prestige.
Arabic is the official language of Islam, and anywhere that Islam goes, Arabic goes with it. Arabic is an official language in almost all of northern Africa, the middle east, and many parts of southern Asia.
Russia is huge. Russia also interacts with its huge neighbors. Lastly, Russian influence is found in many languages in eastern Europe, giving people wanting to learn those too a leg up. Russia also has a reasonably big economy, although it got hurt in recent years.
Hindi is India's most populous language. Urdu is very similar. (Although the two are slowly further diverging. Hindi prefers to dig though the ancient Indian language of Sanskrit for further terminology, whereas Urdu prefers Arabic for this purpose.)
Portugal doesn't appear much in the news these days, but their former colony, Brazil, does.
Even if every Icelandic person abandoned this language in favor of English, historians would preserve it, as it draws from the very root language of English, German, Norweigian, Swedish, and Danish. Icelandic has literally not changed in a thousand years, which is rare for a language.
Esperanto is nobody's native language, and was invented by a Polish linguist to solve the problem of five different linguistic groups wanting to communicate, but none of them satisfied with any party having the advantage of using their own native language. It flopped there, but is favored in Asia as..well, nobody's language that draws from every European language. Therefore, if you know Esperanto, learning any European language is easy. Also, Esperanto has no irregular verbs due to it being artificial. No irregular verbs makes it that much easier to learn.
These three languages are connected, and I'm not sure which one deserves the place. Will they combine into each other, or diverge further?
Finish is unrelated to the languages of any of Finland's neighbors, which is strange. Finland is starting to experiment with cultural exportation.
Better known as "Navajo," because it is the native language of that tribe. Quite famous from its cryptographic use in World War II.
English might be ubiquitous in both the Netherlands and Belgium, but I don't see either one giving up on Dutch.
Hebrew died down to just the liturgical language of Judaism in the past, but underwent a revival from the founding of Israel.
Increasing Iranian influence will increase the influence of this Iranian language.
Poland was conquered for much of the end of the 19th century and beginning of the 20th. When officially restored, the Polish people were quite nationalistic about it.
Latin is officially dead and possibly no longer pronounced correctly, but is an official liturgical language of the Catholic church, the ancestor of many European languages, present in many legal terminologies, and lastly, "Quid quid latine dictum sit, altum videtur."