Slovenski dijalekti glavni su izvor za rekonstrukciju razvoja slovenskoga jezika, od praslavenskoga dijalekta koji su govorili Slaveni u Alpama i na Krasu od doseljenja koncem VI. do X./XI. stoljeća, ...naovamo. U slovenskim su dijalektima "zapisane” sve glavne razvojne faze svih inovacija, od XII. stoljeća do danas.
Slovene dialects are the main source for the reconstruction of the development of the Slovene language, from the proto-Slavic dialect spoken by the Slavs in the Alps and Karst at the time of their ...settlement (from the end of the 6th to 10/ 11th centuries) to the present. Slovene dialects are a record of all the main development stages of the innovations from the 12th century to the present.
The diphtongization of monophthongs and the later monophthongization
of diphthongs are the two most significant developmental
factors of Slovene long vowels. Both occurrences are quite old, the
first ...dates from the 12th—13th century; the second probably from
the 13th—14th century. Up to the 12th century the system of long
Slovene vowels was of a monophthong type. However when in the
12th—13th century the first Slovene diphthongization came about,
the system changed from that of a monophthong type to that of a
diphthong type.