| Aukštaitian | |
| Nativename: | Aukštaičių tarmė |
| States: | Lithuania |
| Region: | Aukštaitija, Dzūkija and Suvalkija |
| Speakers: | ? |
| Familycolor: | Indo-European |
| Fam2: | Balto-Slavic |
| Fam3: | Baltic |
| Fam4: | Eastern |
| Fam5: | Lithuanian |
| Isoexception: | dialect |
| Glotto: | auks1239 |
| Glottorefname: | Aukshtaitish |
Aukštaitian (Lithuanian: Aukštaičių tarmė) is one of the dialects of the Lithuanian language, spoken in the ethnographic regions of Aukštaitija, Dzūkija and Suvalkija. It became the basis for the standard Lithuanian language.
Revised classification of the dialects, proposed in 1965 by linguists Zigmas Zinkevičius and Aleksas Girdenis, divides the Aukštaitian dialect into three sub-dialects based on pronunciation of the mixed diphthongs an, am, en, em and the ogonek vowels ą and ę:
Western Aukštaitianmost similar to standard Lithuanianpreserves both the diphthongs and the vowels. It is further subdivided into two sub-dialects:
Southern Aukštaitian preserves the diphthong, but replaces ą and ę with ų and į (žųsis instead of žąsis 'goose', skįsta instead of skęsta 'drowns'). It is spoken mostly in Dzūkija and therefore is known as the Dzūkian dialect.
Eastern Aukštaitian replaces the diphthongs with either un, um, in, im or on, om, ėn, ėm (pasumda instead of pasamdo 'hiring', romstis instead of ramstis 'support'). The ogonek vowels are replaced with either ų, į or o, ę/ė (grųštas or groštas instead of grąžtas 'drill', grįšt instead of gręžti 'to drill'). It is mostly spoken in Aukštaitija. It is further subdivided into six sub-dialects.