section_path: Proposed external relations
section_name: Proposed external relations
paragraph_text: Proposed external relations
  
  From the very beginning of Indo-European studies, there have been attempts to link the Indo-European languages genealogically to other languages and language families. However, these theories remain highly controversial, and most specialists in Indo-European linguistics are skeptical or agnostic about such proposals.
  
  Proposals linking the Indo-European languages with a single language family include:
  
  Other proposed families include:
  
  Nostratic and Eurasiatic, in turn, have been included in even wider groupings, such as Borean, a language family separately proposed by Harold C. Fleming and Sergei Starostin that encompasses almost all of the world's natural languages with the exception of those native to sub-Saharan Africa, New Guinea, Australia, and the Andaman Islands.