In a world with approximately 4.5 billion people, the six most widespread languages were Mandarin Chinese, Spanish, English, French, Russian and Arabic - also the six official languages of the UN. Also of significant importance were Hindi, Portuguese, Bengali, Japanese, and German.
With the major devastation all over the world, especially the Northern Hemisphere, the worldwide language structure is shaken as well. With the destruction of the old USSR, Japan and Germany, the numbers of Russian, Japanese and especially German native speakers have shrunk dramatically. The worldwide dominance of English is reduced with the lack of the USA, UK and most of Canada. Many European languages have suffered a severe loss of speakers, with some of them going extinct, but others have benefited and increased in usage at the same time. The real cultural heart of English is now the ANZ Commonwealth.
On the contrary, however, Portuguese and especially Spanish are on the rise despite of the devastation of Spain and Portugal, as the economical worldwide activity is centering on the South American continent and ANZC, with the South American nations mostly speaking Portuguese and especially Spanish as national languages.
As China and India are still in a catastrophic state of anarchy, the (global) importance of their respective languages has also become quite limited. The effects of Doomsday and nuclear fallout has reduced their numbers of speakers as well.
Like Portuguese and Castilian, Greek is also seeing a bit of a revival period. With the Confederation of Greece being the major power in the Mediterranean Basin, Libyans, Egyptians, Algerians and even some Sicilians are learning Greek as a second language. Likewise, Arabic is becoming more and more learned by Greeks as a means of communication for the new colonists in the Greek mandates. Some hypothesize that, as the Grecian colonists learn Arabic and the Egyptian natives learn Greek, a pidgin might rise up from the streets of Cyrene, Alexandria, Tripoli or Suez. This new pidgin might even develop into a creole language in the future. As of late 2009 (six years after the Greeks arrived), there has been no reported communication language. Only time will tell.
Present Day, 2014
The linguistic sphere of today is a reflection of over two decades of reconstruction and development. The main languages of international trade and diplomacy are English (Anglo-Australian), Spanish and Portuguese (Brazilian).
Particularly in Europe, French and the Celtic/Gaelic languages have seen a resurgence in their respective spheres; owing to increased cohesion (Francophone community) and political emphasis (Celtic Alliance).
In many areas of the former UK, local dialects have began to evolve into more individual languages. Among these are Northumbrian, Pitmatic, Cumbric (Northumbria) and Cleveish (Cleveland) in the former northeast of England.
South Africa and New Britain have likewise seen a revival of interest in Afrikaans for practical purposes, although Dutch (its linguistic ancestor) is rapidly diminishing in relevance. German (Alpine Confederation, North Germany, German Southwest Africa and Prussia) and Russian (Socialist Siberia) are relegated to "limited" influence by the WCRB, due to the relative isolation of their respective spheres, although both languages do enjoy considerable use and relevance within them.
The fate of Chinese is uncertain, although sizable diaspora communities still uphold them: Chinese in New Britain, ANZC, Taiwan, the USSR and Southeast Asian states. Regional Chinese languages, such as Wu and Yue, have begun to compete with Mandarin Chinese as the principal language of China.
Meanwhile in Socialist Siberia, new creole languages have raised, because of the Han Chinese diaspora. Because communities have become isolated in the former USSR, the language Chagatai, named after Genghis Khan's second son, which in OTL went extinct in 1992, survived in TTL. The Old Prussian language has seen a revival in Prussia.