Autonyms used throughout history by various Kajkavian writers have been manifold, ranging from Slavic (slavonski, slovenski, slovinski) to Croatian (horvatski) or Illyrian (illirski) [REF].
The problem with classifying Kajkavian within South Slavic stems in part from its structural differences from neighboring Shtokavian speeches as well as its historical closeness to Slovene speeches.