Slovene has 24 distinctive consonant phonemes, of those only 21 are more common: /ʋ/ has several allophones depending on context.
The preposition v is always bound to the following word and it is always pronounced as /u̯/ except when standing alone out of a sentence (the pronunciation then is [úː]).
[24] Proto-Slavic consonant clusters *tl and *dl simplified quite soon in central, southern and eastern areas while it disappeared later from western and northern dialects.
The clusters tl and dl that are nowadays present in the standard language became such after the omission of *ь/*ъ between the consonants.
The first Slavic palatalization in nowadays Slovene exists only for /k/, /g/, /x/, and /ts/, which turn into /tʃ/, /ʒ/, /ʃ/, and /tʃ/, respectively:[25] The second Slavic palatalization in today's Slovene exists only for /k/ and /g/, which turn into /ts/ and /z/, respectively:[25] Iotation is the change of a consonant when /j/ follows and they merge together in one or more sounds:[25] When a stop or affricate is followed by another stop or affricate, it dissimilates into a fricative, e. g. bedak [beˈdǎːk] 'idiot' + -ski [ski] → bedaški [beˈdàːʃkí] 'idiotic' and k [k] 'to' + grobu [ˈgrɔ̀ːbú] 'grave' → h grobu [x‿ˈgɾɔ̀ːbú] 'to the grave'.
Consonant clusters in non-assimilated words can be excluded from this rule, for example podcast [ˈpóːdˌkàst] 'podcast'.
[28] Nasal /m/, /n/ also match the place of articulation with the following consonant: Istanbul 'Istanbul' [ˈíːstamˌbùl], informacija 'information' [ˌiɱfoɾˈmàːtsijà], banka 'bank' [ˈbáːŋkà] (but they do not change change articulation before post-alveolar consonants and /m/ also does not have allophone [ŋ]).
Jurgec proposes the existence of a ninth vowel /ʌ/ in tonemic variety that in traditional pronunciation (see below under Prosody) would rather be analyzed as a short /a/.
Due to the restrictions stated above, the open /a/ usually appears in its place in other declinational forms of the same word: časa [ˈtʃàːsá], not [ˈtʃʌ̀ːsá], 'time (gen.)'.
[41] Jurgec also states that in the tonemic varieties of the language, the near-open vowel /ʌ/ can carry only the high tone (see below), which is "parallel to the pattern for the [/ɛ/, /ɔ/ and /ə/]."
"[42] According to Jurgec (2007) harvcoltxt error: no target: CITEREFJurgec2007 (help), /ə/ is inserted epenthetically, and its distribution is fully predictable.
He also says that "[d]escriptions of schwa distribution are offer[ed] in lexical rather than grammatical terms.
"[43] Slovene has been traditionally described as distinguishing vowel length, which correlates with stress and is therefore discussed in the prosody section, below.
[49] In some loanwords, sonorant clusters may be present that are required to form a new syllable in Slovene.
In the colloquial spoken language, unstressed and most short stressed vowels tend to be reduced or elided.
Exceptions are unstressed /i/ and /u̯/, which are pronounced as usual or turn into [j] and [u̯], respectively if preceded by a vowel, e.g, bo imela '(she) will have' [bo‿iˈméːlà] or [bo‿jˈméːlà].
[55] A new change that is currently happening most notably around Ljubljana is the pronunciation of /ə/ as [ɛ] or [e], eliminating another distinction between vowels.
[56] Historically, [ˈsɛm] is the pronunciation of sem in the meaning 'here' and [ˈsəm] for sem in the meaning '(I) am', but due to modern vowel reduction, which is the most prominent in monosyllabic words, and the recent development of /ə/ → /ɛ/ , the roles are nowadays mostly switched, i. e. '(I) am' is now pronounced [ˈsɛm] and 'here' is now pronounced [ˈsəm].
In other syllables, however, whether vowel length or stress, or both, are phonemic depends on the underlying phonological analysis.
Generally speaking, stress and length co-occur in all but the final syllable, so one feature or the other is phonetically redundant in those words.
Standard language allows both accents, but the unshifted one is considered archaic or high literary, as with the pronunciation of /ə/ as [ɛ] or [e], the shift occurs also in Upper and Lower Carniolan dialects.
The first one happened in Tolmin, Cerkno, Črni Vrh, Horjul, Karst, Inner Carniolan, Istrian, Kostel, Čabranka, South White Carniolan and North White Carniolan dialects, as well as all Styrian dialects, except Lower Sava Valley dialect and the second one happened in Gail Valley dialect without the subdialect, Resian, Torre Valley, Črni Vrh, Poljane, eastern part of Rosen Valley, Jaun, Mežica, North Pohorje–Remšnik, Upper Savinja, Central Savinja, South Pohorje, Kostel, Čabranka, North White Carniolan and South White Carniolan dialects.
However, because the Slovenian capital city Ljubljana is located within the central tonemic dialect area, phonemic tone was included in the standard language, and in fact the tonemic variety is more prestigious and is universally used in formal TV and radio broadcasts.
[65] Unless otherwise noted, this article discusses the tonemes as they are realized in Standard Slovene spoken in Ljubljana.
If last syllable is stressed, then they merge and form rising (acute) or falling (circumflex) tone; e.g., pot [ˈpǒːt] / [ˈpôːt] 'path'.
Similarly, for speakers who do not distinguish short and long vowels, the first and third rows merge, as do the second and fourth.