↑ 1.01.1Very rare as an independent phoneme; mostly occurs as an allophone of the nonpalatalized equivalent before /i/ and /ɪ/ in loanwords.
↑ 2.02.12.22.3Sometimes described as retroflex, i.e. [ʂ ʐ ʈ͡ʂ ɖ͡ʐ]. The Serbski Institut asserts that the postalveolars /ʃ/ and /t͡ʃ/ are separate phonemes from /ʂ/ and /ʈ͡ʂ/, but if so, the postalveolars appear almost only in loanwords, and the functional load of the contrast is extremely low.
^ Occurs only in loanwords; not reliably distinguished from /w/ by all speakers.
^ Phonetic realizations vary from a palatalized bilabial to a palatalized labiodental fricative, [vʲ] ~ [βʲ]; generally replaced by /j/ before /a/ and /ɛ/ but may be retained there in careful speech. The Serbski Institut describes it as a palatalized labiovelar approximant, [wʲ], but it is unclear what that is supposed to mean; perhaps [ɥ].
^ Phonetic realizations before a vowel vary from a labiovelar approximant to a velarized bilabial approximant or fricative, [w] ~ [β˕ˠ] ~ [βˠ]. At the end of syllable, always realized as [w].
^ Some but not all speakers have palatalized [xʲ] as an allophone of /x/ after /i/ and /ɪ/.
^ Allophone of /ɛ/ between a “hard” consonant (i.e. any other than /l/ or a palatalized or alveo-palatal consonant) and /x/.
^ Allophone of /ɛ/ before /j/ (regardless of the quality of the preceding consonant), in the word zemja and its derivatives, and between two “soft” consonants (i.e. /l/ or a palatalized or alveo-palatal consonant). Before /j/ in the following syllable there is free variation between the allophones [e] and [ɛ].
^ Allophone of /ɛ/ in unstressed final and antepenultimate open syllables.
↑ 13.013.113.2The letter ⟨ó⟩ represents /ɛ/, /ɨ/, or /ʊ/ depending on dialect; but ⟨ój⟩ is always /ɛj/[ej]. The pronunciation /ʊ/, as in Upper Sorbian, is now only marginal in Lower Sorbian.
^ Replaced with /ɛ/ (in its allophone [e]) in before /j/. The contrast between /ɪ/ and /ɛ/ is lost in unstressed syllables for many speakers in casual speech.
Stone, Gerald (2002), “Sorbian (Upper and Lower)”, in Comrie, Bernard; Corbett, Greville G., The Slavonic Languages, London and New York: Routledge, pp. 593–685, →ISBN.