text: Relationship towards neighboring dialects Shtokavian is characterized by a number of characteristic historical sound changes, accentual changes, changes in inflection, morphology and syntax. Some of these isoglosses are not exclusive and have also been shared by neighboring dialects, and some of them have mostly but not completely spread over the whole Shtokavian area. The differences between Shtokavian and the unrelated, neighboring Bulgarian–Macedonian dialects are mostly clear-cut, whereas the differences with the related Serbo-Croatian dialects of Chakavian and Kajkavian are much more fluid, and the mutual influence of various subdialects plays a more prominent role.
  The main bundle of isoglosses separates Slovenian and Kajkavian on the one hand from Shtokavian and Chakavian on the other. These are:
  long falling accent of newer origin (neocircumflex)
  development of the consonant group rj (as opposed to consonant /r/) from former soft /r'/ before a vowel (e.g., , )
  reflexes of /o/ or /ọ/ of the old Common Slavic nasal vowel /ǫ/, and not /u/
  inflectional morpheme -o (as opposed to -ojo) in the instrumental singular of a-declension
  Other characteristics distinguishing Kajkavian from Shtokavian, beside the demonstrative/interrogatory pronoun kaj (as opposed to što/šta used in Shtokavian), are:
  a reflex of old semivowels of /ẹ/ (e.g. dẹn  /š/ before consonants (c.f. Čk. maška : Št. mačka)
  word-initial consonant groups čr-, čri-, čre- (c.f. Čk. črivo/črevo : Št. cr(ij)evo, Čk. črn : Št. crn)
  conditional mood with biš in the second-person singular
  non-syncretized dative, locative and instrumental plural
  General characteristics
  General characteristics of Shtokavian are the following:
  što or šta as the demonstrative/interrogative pronoun