section_path: Evolution/Important languages for reconstruction
section_name: Important languages for reconstruction
paragraph_text: Important languages for reconstruction
  
  In reconstructing the history of the Indo-European languages and the form of the Proto-Indo-European language, some languages have been of particular importance. These generally include the ancient Indo-European languages that are both well-attested and documented at an early date, although some languages from later periods are important if they are particularly linguistically conservative (most notably, Lithuanian). Early poetry is of special significance because of the rigid poetic meter normally employed, which makes it possible to reconstruct a number of features (e.g. vowel length) that were either unwritten or corrupted in the process of transmission down to the earliest extant written manuscripts.
  
  Most noticeable of all:
  
  Other primary sources:
  
  Other secondary sources, of lesser value due to poor attestation:
  
  Other secondary sources, of lesser value due to extensive phonological changes and relatively limited attestation: