In contrast to Southeastern, which is the literary standard of Ukrainian within Ukraine, Southwestern is common within the Ukrainian diaspora, much of which comes from Western Ukraine.

Among the speakers of the Carpathian dialect group, regardless of stress, historic vowel sounds ō and ē become і, ě becomes 'і, and ę becomes 'а.

In the Galician–Bukovinian dialect group, ě becomes 'е or 'y, and ę becomes 'і.

[2] Historically, the Southwestern dialects also separated foreign loanwords from native Ukrainian words by usage of the /ɡ/ sound for "г" rather than the /ɦ/ typically used for the sound in non-loanwords.

This practice ended following the Ukrainian orthography of 1933 and the Soviet annexation of Eastern Galicia and Volhynia.