text: syncretism of dative, locative and instrumental plural of nouns, with many exceptions
  preservation of ending  in genitive and accusative singular of masculine and neuter gender if pronominal-adjectival declension (e.g., ), with exceptions on the area of Dubrovnik and Livno
  special form with the ending -a for the neuter gender in nominative plural of pronominal-adjectival declension (e.g.  and no )
  preservation of aorist, which is however missing in some areas (e.g., around Dubrovnik)
  special constructs reflecting old dual for numerals 2–4 ()
  many so-called "Turkisms" () or "Orientalisms", i.e. words borrowed from Ottoman Turkish
  As can be seen from the list, many of these isoglosses are missing from particular Shtokavian idioms, just as many of them are shared with neighboring non-Shtokavian dialects.
  There exist three main criteria for the division of Shtokavian dialects:
  Accentuation ("Old-Shtokavian" and "Neo-Shtokavian"; see section below)
  Yat reflex ("Ikavian", "Ijekavian", "Ekavian"; see section below)
  Young Proto-Slavic (600–750 AD) palatal consonant isogloss: *šć-*žƷ ( - Schakavian; "Western Shtokavian" including Slavonian, Eastern Bosnian and transitory Western ikavian dialect) and *št & *žd ( - Shtakavian; "Eastern Shtokavian" including Eastern Herzegovinian-Krajina, Šumadija-Vojvodina, Kosovo-Resava, Zeta-Raška dialect). The isogloss developed between 7th and 8/9th century, and the former relates those dialects with Chakavian and Kajkavian, while the latter relates those dialects with Bulgarian.