|In IPA, phonemes are written between slashes, / /, and corresponding allophones between brackets, [ ].|
This article deals with the phonology and phonetics of Standard Modern Greek. For phonological characteristics of other varieties, see varieties of Modern Greek, and for Cypriot, specifically, see Cypriot Greek § Phonology.
Greek linguists do not agree on which consonants to count as phonemes in their own right, and which to count as conditional allophones. The table below is adapted from Arvaniti (2007, p. 7), who does away with the entire palatal series, and both affricates and .
The alveolar nasal /n/ is assimilated to following obstruents; it can be labiodental (e.g. [a?fivo'lia] 'doubt'), dental (e.g. ['anos] 'flower'), retracted alveolar (e.g. ['pen?sa] "pliers"), alveolo-palatal (e.g. ? [si?'çizo] 'to annoy'), or velar (e.g. ['aos] 'stress').
Voiceless stops are unaspirated and with a very short voice onset time. They may be lightly voiced in rapid speech, especially when intervocalic./t/'s exact place of articulation ranges from alveolar to denti-alveolar, to dental. It may be fricated [ ~ ?] in rapid speech, and very rarely, in function words, it is deleted./p/ and /k/ are reduced to lesser degrees in rapid speech.
Voiced stops are prenasalised as reflected in the orthography to varying extents, or not at all. The nasal component--when present--does not increase the duration of the stop's closure; as such, prenasalised voiced stops would be most accurately transcribed [?b ?d ] or [m?b, n?d, ], depending on the length of the nasal component. Word-initially and after /r/ or /l/, they are very rarely, if ever, prenasalised. In rapid and casual speech, prenasalisation is generally rarer, and voiced stops may be lenited to fricatives. This also accounts for Greeks having trouble disambiguating voiced stops, nasalised voiced stops, and nasalised voiceless stops in borrowings and names from foreign languages; for example, d, nd, and nt, which are all written in Greek.
/s/ and /z/ are somewhat retracted ([s?, z?]); they are produced in between English alveolars /s, z/ and postalveolars /?, ?/./s/ is variably fronted or further retracted depending on environment, and, in some cases, it may be better described as an advanced postalveolar ().
The only Greek rhotic /r/ is prototypically an alveolar tap , often retracted (). It may be an alveolar approximant intervocalically, and is usually a trill in clusters, with two or three short cycles.
Greek has palatals [c, ?, ç, ?] that contrast with velars [k, ?, x, ?] before /a, o, u/, but in complementary distribution with velars before front vowels /e, i/. and occur as allophones of /l/ and /n/, respectively, in CJV (consonant-glide-vowel) clusters, in analyses that posit an archiphoneme-like glide /J/ that contrasts with the vowel /i/. All palatals may be analysed in the same way. The palatal stops and fricatives are somewhat retracted, and and are somewhat fronted. is best described as a postalveolar, and as alveolo-palatal.
The table below, adapted from Arvaniti (2007, p. 25), displays a near-full array of consonant phones in Standard Modern Greek.
|Flap or tap|
Some assimilatory processes mentioned above also occur across word boundaries. In particular, this goes for a number of grammatical words ending in /n/, most notably the negation particles and and the accusative forms of the personal pronoun and definite article and . If these words are followed by a voiceless stop, /n/ either assimilates for place of articulation to the stop, or is altogether deleted, and the stop becomes voiced. This results in pronunciations such as [to(m)ba'tera] ('the father' ACC) or [ðe(m)bi'razi] ('it doesn't matter'), instead of *[ton pa'tera] and *[ðen pi'razi]. The precise extent of assimilation may vary according to dialect, speed and formality of speech. This may be compared with pervasive sandhi phenomena in Celtic languages, particularly nasalisation in Irish and in certain dialects of Scottish Gaelic.
Greek has a system of five vowels /i, u, e, o, a/. The first two have qualities approaching their respective cardinal vowels [i, u], the mid vowels /e, o/ are true-mid [e?, o?] and the open /a/ is near-open central 
There is no phonemic length distinction, but vowels in stressed syllables are pronounced somewhat longer [i?, u?, e?, o?, a?] than in unstressed syllables. Furthermore, vowels in stressed syllables are more peripheral, but the difference is not large. In casual speech, unstressed /i/ and /u/ in the vicinity of voiceless consonants may become devoiced or even elided.
Unlike Ancient Greek, which had a pitch accent system, Modern Greek has variable (phonologically unpredictable) stress. Every multisyllabic word carries stress on one of its three final syllables. Enclitics form a single phonological word together with the host word to which they attach, and count towards the three-syllable rule too. In these cases, primary stress shifts to the second-to-last syllable (e.g. ? [afto?cini'to mu] 'my car'). Phonetically, stressed syllables are longer and/or carry higher amplitude.
The position of the stress can vary between different inflectional forms of the same word within its inflectional paradigm. In some paradigms, the stress is always on the third last syllable, shifting its position in those forms that have longer affixes (e.g. 'I called' vs. 'we called'; 'problem' vs. ? 'problems'). In some word classes, stress position also preserves an older pattern inherited from Ancient Greek, according to which a word could not be accented on the third-from-last syllable if the last syllable was long, e.g. ('man', nom. sg., last syllable short), but ('of men', gen. pl., last syllable long). However, in Modern Greek this rule is no longer automatic and does not apply to all words (e.g. 'monk', 'of monks'), as the phonological length distinction itself no longer exists.
? ? ? ' ? ? , ? ? ? ? ? ? ? ?.
[o vo'as 'co?i?oz 'malonan | ?a to 'pços aptuz 'ð?o 'ineo? ðina'tote?os | 'ota 'netiçe nape'?asi apo bro'status | 'enas taksi'ð?otis pu? fo'?use 'kapa]