The phonological system of the Polish language is similar in many ways to those of other Slavic languages, although there are some characteristic features found in only a few other languages of the family, such as contrasting postalveolar and alveolo-palatal fricatives and affricates, and nasal vowels. The vowel system is relatively simple, with just six oral monophthongs and two nasals, while the consonant system is much more complex.
Traditionally, the Polish vowel system consists of six oral monophthongs and two nasal diphthongs. Vowel nasality in Polish is partially preserved from Proto-Slavic, having been lost in most other modern Slavic languages. However, more recent sources present a vowel system without nasal vowel phonemes.
The vowels /?/ and /i/ have largely complementary distribution. Either vowel may follow a labial consonant, as in mi ('to me') and my ('we'). Elsewhere, however, /i/ is usually restricted to word-initial position and positions after alveolo-palatal consonants and approximants /l, j/, while /?/ cannot appear in those positions (see § Hard and soft consonants below). Either vowel may a velar fricative /x/ but after velar /k, ?/ the vowel /?/ is limited to rare loanwords e.g. kynologia [?k?n?'lja] ('cynology') and gyros ['?s] ('gyro'). Dental, postalveolar consonants and approximants /r, w/ are followed by /?/ in native or assimilated words. However, /i/ appears outside its usual positions in some foreign-derived words, as in chipsy [t?ips?] ('potato chips') and tir [ti?] ('large lorry', see TIR). The degree of palatalization in these contexts is weak. In some phonological descriptions of Polish that make a phonemic distinction between palatized and unpalatized consonants, and may thus be treated as allophones of a single phoneme. In the past, /?/ was closer to , which is acoustically more similar to .
Nasal vowels do not feature uniform nasality over their duration. Phonetically, they consist of an oral vowel followed by a nasal semivowel or (s? is pronounced [s?w?], which sounds closer to Portuguese são [sw?] than French sont [s] - all three words mean "[they] are"). Therefore, they are phonetically diphthongs. (For nasality following other vowel nuclei, see § Allophony below.)
Nasal phonemes /, / appear in older phonological descriptions of Polish e.g. Stieber (1966), Roc?awski (1976:84), Wierzchwoska (1980:51) harvcoltxt error: no target: CITEREFWierzchwoska1980 (help). In more recent descriptions orthographical nasal vowels ?, ? are analyzed as two phonemes in all contexts e.g. Sawicka (1995), Wi?niewski (2007). Before a fricative and in word-final position they are transcribed as an oral vowel /?, ?/ followed by a nasal consonant /?, ?/ or /j?, w?/. Under such an analysis, the list of consonantal phonemes is extended by a velar nasal phoneme /?/ or by two nasal approximants /j?/, /w?/.
If analyzed as separate phonemes, nasal vowels do not occur except before a fricative and in word-final position. When the letters ? and ? appear before stops and affricates, they indicate an oral /?/ or /?/ followed by a nasal consonant homorganic with the following consonant. For example, k?t is [k?nt] ('angle'), g?ba ('mouth') is ['mba], pi ('five') is [pjt] and b?k is [bk] ('bumble bee'), as if they were spelled *kont, *gemba, *pie and *bonk. Before /l/ or /w/, nasality is lost altogether and ? and ? pronounced as oral or . The // phoneme is also denasalized to in word-final position, as in b?d? ['b?nd?] "I will be".
|/i/||i||mi? [m?i?] ('teddy bear')|
|/?/||e||ten [t?n] ('this one')|
|/?/||y||mysz [m] ('mouse')|
|/a/||a||ptak [ptak] ('bird')|
|/u/||u/ó||bum [bum] ('boom')|
|/?/||o||kot [k?t] ('cat')|
|// (or //)||?||w??e [v?w] ('snakes')|
|// (or //)||?||w?? [v?w] ('snake')|
Distinctive vowel length was inherited from late Proto-Slavic, with some changes (for example, stressed acute and circumflex vowels, and some long vowels occurring after the stress, were shortened). Additional vowel lengths were introduced in Proto-Polish (as in other West Slavic languages) as a result of compensatory lengthening when a yer in the next syllable disappeared. If a yer (or other vowel) disappeared, the preceding vowel became long (unless it was also a yer, in which case it became a short e).
This system of vowel lengths is well preserved in Czech and to a lesser degree in Slovak. In the emerging modern Polish, however, the long vowels were shortened again but sometimes (depending on dialect) with a change in quality (the vowels tended to become higher). The latter changes came to be incorporated into the standard language only in the case of long o and the long nasal vowel, mostly for vowels located before voiced obstruents. The vowel shift may thus be presented as follows:
Note that the /u/ that was once a long /o:/ is still distinguished in script as ó. Former long /e:/ was written é until the 19th century (á for former long /a:/ had already fallen into disuse).
In most circumstances, consonants were palatalized when followed by an original front vowel, including the soft yer (?) that was often later lost. For example: *d?n? became dzie? ('day'), while *d?n?m? became dniem ('day' instr.).
Nasal vowels *? and *? of late Proto-Slavic merged (*? leaving a trace by palatalizing the preceding consonant) to become the medieval Polish vowel /ã/, written ø. Like other Polish vowels, it developed long and short variants. The short variant developed into present-day // ?, while the long form became //, written ?, as described above. Overall:
The historical shifts are the reason for the alternations o:ó and ?:? commonly encountered in Polish morphology: *rog? ('horn') became róg due to the loss of the following yer (originally pronounced with a long o, now with /u/), and the instrumental case of the same word went from *rog?m? to rogiem (with no lengthening of the o). Similarly, *d?b? ('oak') became d?b (originally with the long form of the nasal vowel), and in the instrumental case, *d?b?m? the vowel remained short, causing the modern d?bem.
Polish dialects differ particularly in their realization of nasal vowels, both in terms of whether and when they are decomposed to an oral vowel followed by a nasal consonant and in terms of the quality of the vowels used.
Also, some dialects preserve nonstandard developments of historical long vowels (see previous section); for example, a may be pronounced with [?] in words in which it was historically long.
The Polish consonant system is more complicated; its characteristic features include the series of affricates and palatal consonants that resulted from four Proto-Slavic palatalizations and two further palatalizations that took place in Polish and Belarusian.
|IPA||Polish script||Example||IPA||Polish script||Example|
|/m/||m||masa ('mass')||/?/||?/n(i)||ko? ('horse')|
|/b/||b||bas ('bass')||/?/||?/z(i)||?rebi? ('foal')|
|/p/||p||pas ('belt')||/?/||?/s(i)||?ruba ('screw')|
|/v/||w||wór ('bag')||/d/||d?/dz(i)||d?wi?k ('sound')|
|/f/||f||futro ('fur')||/t/||?/c(i)||?ma ('moth')|
|/n/||n||noga ('leg')||/?/||?/rz||?ona ('wife') rzeka ('river')|
|/d/||d||dom ('home')||/?/||sz||szum ('rustle')|
|/t/||t||tom ('volume')||/d/||d?||d?em ('jam')|
|/z/||z||zero ('zero')||/t/||cz||czas ('time')|
|/s/||s||sum ('catfish')||/?/||n(k)/n(g)||bank ('bank'), gong ('gong')|
|/d?z/||dz||dzwon ('bell')||/?/||g||gmin ('populace')|
|/t?s/||c||co ('what')||/k/||k||kmin ('cumin'), buk ('beech tree')|
|/r/||r||krok ('step')||/x/||h/ch||hak ('hook'), chór ('choir')|
|/l/||l||pole ('field'), li ('leaf')||(//)||g(i)||gips ('plaster cast')|
|/j/||j||jutro ('tomorrow')||(/k?/)||k(i)||kiedy ('when')|
|/w/||?||ma?y ('small'), ?aska ('grace')||(/x?/)||h(i)/ch(i)||historia ('history'), chichot ('giggle')|
The postalveolar sounds (sz, ?, cz, d?) and the corresponding alveolo-palatals (?, ?, ?, d?) both sound similar to the English palato-alveolar consonants (the sh and ch sounds and their voiced equivalents). The tongue shape of the postalveolar sounds is similar to the shape postalveolar approximant (one of the realization of the English /r/ phoneme, see also Pronunciation of English /r/). The alveolo-palatals are pronounced with the body of the tongue raised to the hard palate but a greater area of the front of the tongue is raised close to the hard palate compared to the English palato-alveolar sounds. The series are known as "rustling" (szeleszcz?ce) and "humming" (szumi?ce) respectively; the equivalent alveolar series (s, z, c, dz) is called "hissing" (sycz?ce).
The distinction is lost in some Lesser Polish dialects.
For the possibility of an additional velar fricative /?/ for ⟨h⟩, see § Dialectal variation below. On the same grounds as for /x?/ Sawicka (1995:146) gives // a phonemic status for speakers who have /?/ in their system.
Polish, like other Slavic languages, permits complex consonant clusters, which often arose from the disappearance of yers (see § Historical development above). Polish can have word-initial and word-medial clusters of up to four consonants, whereas word-final clusters can have up to five consonants. Examples of such clusters can be found in words such as bezwzgl?dny [b?z'vz?l?ndn?] ('absolute' or 'heartless', 'ruthless'), ?d?b?o ['?dbw?] ('blade of grass'), wstrz?s ['fstw?s] ('shock'), and krn?brno ['krn?mbrnt] ('disobedience'). A popular Polish tongue-twister (from a verse by Jan Brzechwa) is W Szczebrzeszynie chrz?szcz brzmi w trzcinie [f?tb'? 'xwd 'b?mi f't?ti] ('In Szczebrzeszyn a beetle buzzes in the reed').
For the restrictions on combinations of voiced and voiceless consonants in clusters, see § Voicing and devoicing below. Unlike languages such as Czech, Polish does not have syllabic consonants: the nucleus of a syllable is always a vowel.
The consonant /j/ is restricted to positions adjacent to a vowel. It also cannot precede i or y. (For other restrictions on consonants appearing before i or y, see § Distribution above.)
Polish obstruents (stops, affricates and fricatives) are subject to voicing and devoicing in certain positions. This leads to neutralization of voiced/voiceless pairs in those positions (or equivalently, restrictions on the distribution of voiced and voiceless consonants). The phenomenon applies in word-final position and in consonant clusters.
In Polish consonant clusters, including across a word boundary, the obstruents are all voiced or all voiceless. To determine (based on the spelling of the words) whether a given cluster has voiced or voiceless obstruents, the last obstruent in the cluster, excluding w or rz (but including ?), should be examined to see if appears to be voiced or voiceless. The consonants n, m, ?, r, j, l, ? do not represent obstruents and so do not affect the voicing of other consonants; they are also usually not subject to devoicing except when surrounded by unvoiced consonants. Some examples follow (click the words to hear them spoken):
Utterance-finally, obstruents are pronounced voiceless. For example, the /?/ in bóg ('god') is pronounced [k], and the /zd/ in zajazd ('inn') represents a pronunciation like [st]. If followed by a word beginning with a obstruent then the above cluster rules apply across morpheme boundaries. When the second word begins with a sonorant the voicing of any preceding word-final obstruent varies regionally. In western and southern Poland, final obstruents are voiced (voicing pronunciation) if the following word starts with a sonorant (here, for example, the /t/ in brat ojca 'father's brother' would be pronounced as [d]). On the other hand, they are voiceless (devoicing pronunciation) in eastern and northern Poland (/t/ is pronounced [t]). This rule does not apply to prepositional clitics w, z, bez, przez, nad, pod, od, przed which are always voiced before sonorants. 
|Final||Initial||voicing pronunciation||devoicing pronunciation|
|Word final obstruent or
Obstruent + /m, n, l, r, j, w/
|Sonorant: /m, n, l, r, j, w, i, ?, ?, a, ?, u/||kot rudy ('a ginger cat')
d?ug ma?y ('a small debt')
kot ?aciaty ('a speckled cat')
d?ug ?ukasza ('Luke's debt')
kot Ewy ('Eve's cat')
m?? Ewy ('Eve's husband')
|Voiceless obstruent: /p, f, t, t?s, s, t, ?, t, ?, k, x, (k?), (x?)/||rok Smoka ('the Year of the Dragon')
róg sto?u ('a table corner')
wiatr szumi ('the wind rustles')
kadr filmu ('a film frame')
|Voiced obstruent: /b, v, d, d?z, z, d, ?, d, ?, ?, (?), (), ()/||porad? Zosi ('give Zosia some advise')
rok dobry ('a good year')
id? zaraz ('go right now')
p?ot br?zowy ('a brown fence')
|Prepositional clitic: w, z, bez, przez, nad, pod, od, przed||Sonorant: /m, n, l, r, j, w, i, ?, ?, a, ?, u/||od matki ('from the mother')
od ??ki ('from a meadow')
od ojca ('from the father')
|Voiceless obstruent: /p, f, t, t?s, s, t, ?, t, ?, k, x, k?, x?/||pod p?otem ('at/by the fence')||[p?t?pw?t?m]|
|Voiced obstruent: /b, v, d, d?z, z, d, ?, d, ?, ?, (?), , ()/||pod dzwonnic? ('beneath a bell tower')||[p?d?d?zv:it?s?w?]|
Multiple palatalizations and some depalatalizations that took place in the history of Proto-Slavic and Polish have created quite a complex system of what are often called 'soft' and 'hard' consonants. These terms are useful in describing some inflection patterns and other morphological processes, but exact definitions of 'soft' and 'hard' may differ somewhat.
'Soft' generally refers to the palatal nature of a consonant. The alveolo-palatal sounds ?, ?, ?, ?, d? are considered soft, as normally is the palatal j. The l sound is also normally classed as a soft consonant: like the preceding sounds, it cannot be followed by y but takes i instead. The palatalized velars /k?/, // and /x?/ might also be regarded as soft on this basis.
Consonants not classified as soft are dubbed 'hard'. However, a subset of hard consonants, c, dz, sz, ?/rz, cz, d?, often derive from historical palatalizations (for example, rz usually represents a historical palatalized r) and behaves like the soft consonants in some respects (for example, they normally take e in the nominative plural). These sounds may be called 'hardened' or 'historically soft' consonants.
In some phonological descriptions of Polish, however, a greater number of consonants, including especially the labials m, p, b, f, w, are regarded as occurring in 'hard' and 'soft' pairs. In this approach, for example, the word pies ('dog') is analyzed not as /pj?s/ but as /ps/, with a soft /p?/. These consonants are then also analyzed as soft when they precede the vowel /i/ (as in pi? /p?it/ 'to drink'). Unlike their equivalents in Russian, these consonants cannot retain their softness in the syllable coda (when not followed by a vowel). For example, the word for 'carp' has the inflected forms karpia, karpie etc., with soft /p?/ (or /pj/, depending on the analysis), but the nominative singular is karp, with a hard /p/.
The consonants t, d, r (and some others) can also be regarded as having hard and soft forms according to the above approach, although the soft forms occur only in loanwords such as tir /t?ir/ ('large lorry'; see TIR). If the distinction is made for all relevant consonants, then y and i can be regarded as allophones of a single phoneme, with y following hard consonants and i following soft ones (and in initial position).
The historical palatalized forms of some consonants have developed in Polish into noticeably different sounds: historical palatalized t, d, r have become the sounds now represented by ?, d?, rz respectively. Similarly palatalized s, z, n became the sounds ?, ?, ?. The palatalization of labials has resulted (according to the main phonological analysis given in the sections above) in the addition of , as in the example pies just given. These developments are reflected in some regular morphological changes in Polish grammar, such as in noun declension.
In more contemporary Polish, a phonetic glottal stop may appear as the onset of a vowel-initial word (e.g. Ala [?ala]). It may also appear following word-final vowels to connote particular affects; for example, nie ('no') is normally pronounced , but may instead be pronounced  or in a prolonged interrupted [?]. This intervocalic glottal stop may also break up a vowel hiatus, even when one appears morpheme-internally, as in poeta ('poet') [pta] or Ukraina ('Ukraine') [?ukra?ina]. A relatively new phenomenon in Polish is the expansion of the usage of glottal stops. In the past, initial vowels were pronounced with an initial voiceless glottal fricative (so that Ala was pronounced [hala]), pre-iotation (so that ig?a 'needle' was pronounced [ji?u?a]), or pre-labialization (so that oko 'eye' was pronounced [uk?]).
In some Polish dialects (found in the eastern borderlands and in Upper Silesia) there is an additional voiced velar fricative /?/, represented by the letter ⟨h⟩. It may be actually a voiced glottal fricative [?] for some speakers, especially word-finally. In most varieties of Polish, both ⟨h⟩ and ⟨ch⟩ represent /x/.
Some eastern dialects also preserve the velarized dental lateral approximant, , which corresponds with [w] in most varieties of Polish. Those dialects also can palatalize /l/ to [l?] in every position, but standard Polish does so only allophonically before /i/ and /j/.  and [l?] are also common realizations in native speakers of Polish from Lithuania, Belarus and Ukraine.
Roc?awski (1976) notes that students of Polish philology were hostile towards the lateral variant of ⟨?⟩, saying that it sounded "unnatural" and "awful". Some of the students also said that they perceived the lateral ⟨?⟩ as a variant of ⟨l⟩, which, he further notes, along with the necessity of deciding from context whether the sound meant was /w/ or /l/, made people hostile towards the sound. On the other hand, some Poles view the lateral variant with nostalgia, associating it with the elegant culture of interwar Poland.
In the Masurian dialect and some neighboring dialects, mazurzenie occurs: postalveolar /?, ?, t, d/ merge with the corresponding dentals /s, z, t?s, d?z/ unless /?/ is spelled ⟨rz⟩ (a few centuries ago, it represented a fricative trill /r?/, distinct from /?/; only the latter sound occurs in modern Polish).
The predominant stress pattern in Polish is penultimate: the second-last syllable is stressed. Alternating preceding syllables carry secondary stress: in a four-syllable word, if the primary stress is on the third syllable, there will be secondary stress on the first.
Each vowel represents one syllable although the letter i normally does not represent a vowel when it precedes another vowel (it represents /j/, palatalization of the preceding consonant, or both depending on analysis; see Polish orthography and the above). Also, the letters u and i sometimes represent only semivowels after another vowel, as in autor /'awt?r/ ('author'), mostly in loanwords (so not in native nauka /na'u.ka/ 'science, the act of learning', for example, nor in nativized Mateusz /ma'te.u?/ 'Matthew').
Some loanwords, particularly from classical languages, have the stress on the antepenultimate (third-last) syllable. For example, fizyka (/'fiz?ka/) ('physics') is stressed on the first syllable. That may lead to a rare phenomenon of minimal pairs differing only in stress placement: muzyka /'muz?ka/ 'music' vs. muzyka /mu'z?ka/ - genitive singular of muzyk 'musician'. When further syllables are added at the end of such words through suffixation, the stress normally becomes regular: uniwersytet (/u?i'v?rs?t?t/, 'university') has irregular stress on the third (or antepenultimate) syllable, but the genitive uniwersytetu (/u?iv?rs?'t?tu/) and derived adjective uniwersytecki (/u?iv?rs?'t?t?sk?i/) have regular stress on the penultimate syllables. Over time, loanwords become nativized to have a penultimate stress.
Another class of exceptions is verbs with the conditional endings -by, -bym, -by?my etc. Those endings are not counted in determining the position of the stress: zrobi?bym ('I would do') is stressed on the first syllable and zrobiliby?my ('we would do') on the second. According to prescriptive grammars, the same applies to the first and second person plural past tense endings -?my, -?cie although this rule is often ignored in colloquial speech (so zrobili?my 'we did' is said to be correctly stressed on the second syllable, although in practice it is commonly stressed on the third as zrobili?my). The irregular stress patterns are explained by the fact that these endings are detachable clitics rather than true verbal inflections: for example, instead of kogo zobaczyli?cie? ('whom did you see?') it is possible to say kogo?cie zobaczyli? - here kogo retains its usual stress (first syllable) in spite of the attachment of the clitic. Reanalysis of the endings as inflections when attached to verbs causes the different colloquial stress patterns.
Some common word combinations are stressed as if they were a single word. That applies in particular to many combinations of preposition plus a personal pronoun, such as do niej ('to her'), na nas ('on us'), przeze mnie ('because of me'), all stressed on the bolded syllable.