The Kajkavian speech area borders in the northwest on the
Slovene language and in the northeast on the
Hungarian language. In the east and southeast it is bordered by Štokavian dialects roughly along a line that used to serve as the border between
Civil Croatia and the
Habsburg Military Frontier. Finally, in the southwest, it borders Čakavian along the Kupa and Dobra rivers. It is thought by M. Lončarić that historically these borders extended further to the south and east, for example, the eastern border is thought to have extended at least well into modern-day
Slavonia to the area around the town of
Pakrac and
Slatina, while East of it transitional Kajkavian-
Štokavian dialects. The transitional dialects during Ottoman invasion and migrations almost completely vanished. The Croatian capital,
Zagreb, has historically been a Kajkavian-speaking area, and Kajkavian is still in use by its older and (to a lesser extent) by its younger population. Modern Zagreb speech has come under considerable influence from Štokavian. The vast intermingling of Kajkavian and standard Štokavian in Zagreb and its surroundings has led to problems in defining the underlying structure of those speech-groups. As a result, many of the urban speeches (but not rural ones) have been labelled either
Kajkavian koine or
Kajkavian–Štokavian rather than Kajkavian or Štokavian. Additionally, the forms of speech in use exhibit significant sociolinguistic variation. Research suggests that younger Zagreb-born speakers of the Kajkavian koine tend to consciously use more Kajkavian features when speaking to older people, showing that such features are still in their linguistic inventory even if not used at all times. However, the Kajkavian koine is distinct from Kajkavian as spoken in non-urban areas, and the mixing of Štokavian and Kajkavian outside of urban settings is much rarer and less developed. The Kajkavian koine has also been named
Zagreb Štokavian by some. The Zagreb variety of Štokavian is considered by some to enjoy parallel prestige with the prescribed Štokavian variety. Because of that, speakers whose native speech is closer to the standard variety often end up adopting the Zagreb speech for various reasons. Kajkavian is closely related to Slovene – and to
Prekmurje Slovene in particular. Higher amounts of correspondences between the two exist in inflection and vocabulary. The speakers of the Prekmurje dialect are
Slovenes and
Hungarian Slovenes who belonged to the
Archdiocese of Zagreb during the Habsburg era (until 1918). They used Kajkavian as their liturgical language, and by the 18th century, Kajkavian had become the standard language of Prekmurje. Moreover, literary Kajkavian was also used in neighboring
Slovene Styria during the 17th and 18th centuries, and in parts of it, education was conducted in Kajkavian. As a result of various factors, Kajkavian has numerous differences compared to Štokavian: • Kajkavian has a prothetic
v- generalized in front of
u (compare Kajkavian
vuho, Štokavian
uho; Kajkavian
vugel, Štokavian
ugao; Kajkavian
vučil, Štokavian
učio). This feature has been attested in Glagolitic texts very early on, already around the 15th century (Petrisov zbornik, 1468). A similar feature exists in
colloquial Czech, as well as in many
Slovene dialects, especially from the
Pannonian,
Styrian and
Littoral dialect groups. • Proto-Slavic *dj resulted in Kajkavian
j as opposed to Štokavian
đ (cf. Kajkavian
meja, Štokavian
međa, Slovene
meja). • The nasal *ǫ has evolved into a closed /o/ in Kajkavian (cf. Kajkavian
roka, Štokavian
ruka, Slovene
roka). • Common Slavic *v and *v- survived as
v in Kajkavian, whereas in Štokavian they resulted in
u and
u-, and in Čakavian they gave way to
va. The same feature is maintained in most Slovene dialects. • Kajkavian has retained /č/ in front of /r/ (cf. Kajkavian
črn,
črv, Štokavian
crn,
crv, Slovene
črn,
črv). • Kajkavian /ž/ in front of a vowel turns into /r/. A similar evolution happened in Slovene, Čakavian as well as Western Štokavian, however the latter does not use it in its standard form (cf. Kajkavian
moči > morem/moreš/more, Štokavian
moći > mogu/možeš/može, Slovene
moči > morem/moreš/more). • Diminutive suffixes in Kajkavian are
-ek,
-ec,
-eko,
-eco (cf. Kajkavian
pes > pesek, Štokavian
pas > psić). The same diminutive suffixes are found in Slovene. • Negative past-tense construction in Kajkavian deviates syntactically from neighboring speeches in its placing of the negative particle. Some argued that this might indicate a remnant of the Pannonian Slavic system. Similar behavior occurs in Slovak (compare Kajkavian
ja sem nę čul, Slovene
jaz nisem čul, Štokavian
ja nisam čuo). • Some variants of Kajkavian have a different first-person plural present-tense suffix,
-mę (cf. Kajkavian
-mę,
rečemę, Slovene
-mo,
rečemo, Štokavian
-mo,
kažemo, Slovak
-me,
povieme) such as the Bednja dialect, although most Kajkavian sub-dialects retain the suffix
-mo. • Relative pronouns differ from neighboring dialects and languages (although they are similar to Slovene). Kajkavian uses
kateri,
tęri and
šteri depending on sub-dialect (cf. Czech
který, Slovak
ktorý, Štokavian
koji, standard Slovene
kateri,
Carniolan dialects ''k'teri
, kęri''). • Kajkavian retains the older locative plural (compare Kajkavian
prsti,
prsteh, Štokavian
prsti,
prstima, Slovene
prsti,
prstih). • The loss of the
dual is considered to be significantly more recent than in Štokavian. • Kajkavian has no
aorist. The same is true for Slovene. • The
supine has been retained as distinctive from infinitive, as in Slovene. The infinitive suffixes are
-ti,
-či whereas their supine counterparts are
-t,
-č. The supine and the infinitive are often stressed differently. The supine is used with verbs of motion. • The future tense is formed with the auxiliary
biti and the
-l participle as in standard Slovene and similar to Czech and Slovak (compare Kajkavian
išel bom, Štokavian
ići ću, standard Slovene
šel bom, eastern Slovene dialects
išel bom). • Kajkavian exhibits various syntactic influences from German. • The Slavic prefix u- has a
vi- reflex in some dialects, similar to Czech
vý- (compare Kajkavian
vigled, Czech
výhled, Štokavian
izgled). This feature sets Kajkavian apart from Slovene, which shares the prefix -iz with Štokavian. In addition to the above list of characteristics that set Kajkavian apart from Štokavian, research suggests possible a closer relation with Kajkavian and the
Slovak language, especially with the Central Slovak dialects upon which standard Slovak is based. As modern-day Hungary used to be populated by Slavic-speaking peoples prior to the arrival of Hungarians, there have been hypotheses on possible common innovations of future West and South Slavic speakers of that area. Kajkavian is the most prominent of the South Slavic speeches in sharing the most features that could potentially be common
Pannonian innovations. Some Kajkavian words bear a closer resemblance to other Slavic languages such as
Russian than they do to Štokavian or Čakavian. For instance
gda (also seen as shorter "da") seems to be at first glance unrelated to
kada, however when compared to Russian
когда, Slovene
kdaj, or Prekmurje Slovene
gda,
kda, the relationship becomes apparent. Kajkavian
kak (
how) and
tak (
so) are exactly like their Russian cognates and Prekmurje Slovene compared to Štokavian, Čakavian, and standard Slovene
kako and
tako. (This vowel loss occurred in most other Slavic languages; Štokavian is a notable exception, whereas the same feature in
Macedonian is probably not due to Serbo-Croatian influence because the word is preserved in the same form in
Bulgarian, to which Macedonian is much more closely related than to Serbo-Croatian). ==Phonology==