Diachronically, Persian possessed a distinction of length in its underlying vowel inventory, contrasting the long vowels /iː/, /uː/, /ä/ with the short vowels /e/, /o/, /æ/ respectively. /e/ is pronounced between the vowel of bate (for most English dialects) and the vowel of bet; /o/ is pronounced between the vowel of boat (for most English dialects) and the vowel of raw.
Word-final /o/ is rare except for /to/ ('you' [singular]), loanwords, and proper and common nouns of foreign origin, and word-final /æ/ is very rare in Iranian Persian, except for /næ/ ('no'). The word-final /æ/ in Early New Persian mostly shifted to /e/ in contemporary Iranian Persian (often romanized as "eh", meaning [e] is also an allophone of /æ/ in word-final position in contemporary Iranian Persian), but is preserved in the Eastern dialects.
The chart to the right reflects the vowels of many educated Persian speakers from Tehran.
Several diphthongs occur in Persian, including /ej/, /aw/, /ow/, /aj/, /ɒj/, /oj/, and /uj/. /aj/~/ej/ and /aw/~/ow/ in Early New Persian become /ej/ and /ow/ respectively in modern Iranian Persian, but are retained in Eastern dialects. /ow/ becomes [o] in colloquial Tehrani dialect but is preserved in other Western dialects and standard Iranian Persian.
|Phoneme (in IPA)||Letter||Romanization||Example(s)|
|/æ/||َ||a, æ||/næ/ نه 'no'|
|/ɒ/||آ , ا||a, á, aa, ā, â, A||/tɒː/ تا 'till'|
|/e̞/||ِ||e||/ke/ که 'that'|
|/iː/||ی||i, ee||/kiː/ کی 'who' (informal)|
|/o̞/||ُ , و||o||/to/ تو 'you' (singular)|
|/uː/||و||u, oo, ou||/tuː/ تو 'in' (informal)|
|Diphthong (in IPA)||Letter||Romanization||Example(s)|
|/ej/||ی||ey, ei, ay, ai||/kej/ کی 'when'|
|/ow/||و||ow, au, ou||/now/ نو 'new'|
|Iranian||e||ī||o||ū||a (in initial and middle positions)||ā|
|e (in word-final position)|
In loanwords and given names of Arabic origin, /aː/ and /ɑ/ became /ɒː/ in Early New Persian and modern Iranian Persian and Dari and /oː/ in modern Tajik, /a/ and /æ/ became /æ/ in Early New Persian and modern Persian (word-final /a/ is allophonized to /e/ in modern Iranian Persian, but /æ/ is retained in modern Dari and Tajik dialects), /e/ and /i/ in Arabic and Early New Persian became /e/ in both modern Dari and Iranian Persian and /i/ in modern Tajik, /o/ and /u/ in Arabic and Early New Persian became /o/ in both modern Dari and Iranian Persian and /u/ in modern Tajik, /eː/ and /iː/ in Arabic and Early New Persian became /iː/ in modern Iranian Persian but became /eː/ and /i/ respectively in modern Dari and Tajik, and /oː/ and /uː/ in Arabic and Early New Persian became /uː/ in modern Iranian Persian but became /oː/ and /u/ respectively in modern Dari and /ɵ/ (usually romanized as ů) and /u/ in modern Tajik.
|Stop||p b||t d||k ɡ||[q ɢ]||ʔ|
|Fricative||f v||s z||ʃ ʒ||x ɣ||h|
(Where symbols appear in pairs, the one to the right represents a voiced consonant. Allophones are in phonetic square brackets.)
|Phoneme||Sound (in IPA)||Letter||Romanization||Example|
|/p/||[p]||پ||p||/peˈdæɾ/ پدر (father)|
|/b/||[b]||ب||b||/bærɒːˈdær/ برادر (brother)|
|/t/||[t]||ت , ط||t||/tɒː/ تا 'till'|
|/d/||[d]||د||d||/duːst/ دوست 'friend'|
|/k/||[k]||ک||k||/keʃˈvæɾ/ کشور 'country'|
|/ɡ/||[ɡ]||گ||g||/ɡoˈruːh/ گروه 'group'|
|/ʔ/||[ʔ]||ع , ء||', ʔ||/mæʔˈnɒː/ معنا 'meaning'|
|/tʃ/||[t͡ʃ]||چ||č||/tʃuːb/ چوب 'wood'|
|/dʒ/||[d͡ʒ]||ج||j||/dʒæˈvɒːn/ جوان 'young'|
|/f/||[f]||ف||f||/feˈʃɒːɾ/ فشار 'pressure'|
|/v/||[v]||و||v||/viːˈʒe/ ویژه 'special'|
|/s/||[s]||س , ص , ث||s||/sɒːˈje/ سایه 'shadow'|
|/z/||[z]||ز , ذ , ض , ظ||z||/ɒːˈzɒːd/ آزاد 'free'|
|/ʃ/||[ʃ]||ش||š||/ʃɒːh/ شاه 'king'|
|/ʒ/||[ʒ]||ژ||ž||/ʒɒːˈle/ ژاله 'dew'|
|/x/||[x]||خ||x||/xɒːˈne/ خانه 'house'|
|/ɣ/||[ɣ]||ق , غ||q||/dæɣiːˈɢe/ دقیقه 'minute'|
|/ɢ/||[ɢ]||ق , غ||q||/ɢæˈlæm/ قلم 'pen'|
|/h/||[h]||ه , ح||h||/hæft/ هفت 'seven'|
|/m/||[m]||م||m||/mɒːˈdær/ مادر 'mother'|
|/n/||[n]||ن||n||/nɒːn/ نان 'bread'|
|/ŋ/||[ŋ]||ن||ng, ŋ||/ræŋ/ رنگ 'color'|
|/l/||[l]||ل||l||/læb/ لب 'lip'|
|/ɾ/||[ɾ]||ر||r||/iːˈɾɒːn/ ایران 'Iran'|
|/j/||[j]||ی||y||/jɒː/ یا 'or'|
Alveolar stops /t/ and /d/ are either apico-alveolar or apico-dental. The voiceless obstruents /p, t, tʃ, k/ are aspirated much like their English counterparts: they become aspirated when they begin a syllable, though aspiration is not contrastive. The Persian language does not have syllable-initial consonant clusters (see below), so unlike in English, /p, t, k/ are aspirated even following /s/, as in /hæstæm/ ('I exist'). They are also aspirated at the end of syllables, although not as strongly.
In Classical Persian, غ and ق denoted the original Arabic phonemes, the voiced velar fricative [ɣ] and the voiceless uvular stop [q] (pronounced in Persian as voiced uvular stop [ɢ]), respectively. In modern Tehrani Persian (which is used in the Iranian mass media, both colloquial and standard), there is no difference in the pronunciation of غ and ق, and they are both normally pronounced as a voiced uvular stop [ɢ]; however, when they are positioned intervocalically and unstressed, lenition occurs and they tend to be pronounced more like a voiced velar fricative [ɣ].  This allophone is probably influenced by Turkic languages like Azeri and Turkmen. The classic pronunciations of غ and ق are preserved in the eastern variants of Persian (i.e. Dari and Tajiki), as well as in the southern dialects of the modern Iranian variety (e.g. Yazdi and Kermani dialects).
The alveolar flap /ɾ/ has a trilled allophonic variant [r] at the beginning of a word, as in Spanish, Catalan, and other Romance languages in Spain; trill [r] as a separate phoneme occurs word-medially especially in loanwords of Arabic origin as a result of gemination of [ɾ].
The pronunciation of و [w] in Classical Persian shifted to [v] in Iranian Persian, but is retained in Dari or Afghan Persian; but in Iranian Persian [v] allophonizes to [w] if preceded by consonant and followed by vowel in one whole syllable, as Persian has no syllable-initial consonant clusters (see below).
Persian syllable structure consists of an optional syllable onset, consisting of one consonant; an obligatory syllable nucleus, consisting of a vowel optionally preceded by and/or followed by a semivowel; and an optional syllable coda, consisting of one or two consonants. The following restrictions apply:
- Consonant (C): Can be any consonant. (Onset is composed only of one consonant; consonant clusters are only found in loanwords, sometimes an epenthetic /æ/ is inserted between consonants.)
- Semivowel (S)
- Vowel (V)
- Semivowel (S)
- First consonant (C): Can be any consonant.
- Second consonant (C): Can also be any consonant (mostly /d/, /k/, /s/, /t/, & /z/).
One syllable in each word (or breath group) is stressed, and knowing the rules is conducive to proper pronunciation.
- Stress falls on the last stem syllable of most words.
- Stress falls on the first syllable of interjections, conjunctions and vocatives. E.g. /ˈbæle/ ('yes'), /ˈnæxeir/ ('no, indeed'), /ˈvæli/ ('but'), /ˈtʃeɾɒ/ ('why'), /ˈæɡæɾ/ ('if'), /ˈmeɾsi/ ('thanks'), /ˈxɒnom/ ('Ma'am'), /ˈɒɢɒ/ ('Sir'); cf. 4-4 below.
- Never stressed are:
- personal suffixes on verbs (/-æm/ ('I do..'), /-i/ ('you do..'), .., /-ænd/ ('they do..') (with one exception, cf. 4-1 below);
- a small set of very common noun enclitics: the /ezɒfe/ (/-e/, /-je) ('of'), /-ɾɒ/ a direct object marker, /-i/ ('a'), /-o/ ('and');
- the possessive and pronoun-object suffixes, /-æm/, /-et/, /-eʃ/, &c.
- Always stressed are:
- the personal suffixes on the positive future auxiliary verb (the single exception to 3-1 above);
- the negative verb prefix /næ-/, /ne-/, if present;
- if /næ-/, /ne-/ is not present, then the first non-negative verb prefix (e.g. /mi-/ ('-ing'), /be-/ ('do!') or the prefix noun in compound verbs (e.g. /kɒr/ in /ˈkɒr mi-kærdæm/);
- the last syllable of all other words, including the infinitive ending /-æn/ and the participial ending /-te/, /-de/ in verbal derivatives, noun suffixes like /-i/ ('-ish') and /-eɡi/, all plural suffixes (/-hɒ/, /-ɒn/), adjective comparative suffixes (/-tæɾ/, /-tæɾin/), and ordinal-number suffixes (/-om/). Nouns not in the vocative are stressed on the final syllable: /xɒˈnom/ ('lady'), /ɒˈɢɒ/ ('gentleman'); cf. 2 above.
- In the informal language, the present perfect tense is pronounced like the simple past tense. Only the stress distinguishes between these tenses: the stressed personal suffix indicates the present perfect and the unstressed one the simple past tense:
|/diːˈde.æm/||/diːˈdæm/||'I have seen'|
Colloquial Iranian Persian
When spoken formally, Iranian Persian is pronounced as written. But colloquial pronunciation as used by all classes makes a number of very common substitutions. Note that Iranians can interchange colloquial and formal sociolects in conversational speech. They include:
- In the Tehrani accent and also most of the accents in Central and Southern Iran, the sequence /ɒn/ in the colloquial language is nearly always pronounced [un]. The only common exceptions are high prestige words, such as [ɢoɾʔɒn] ('Qur'an'), and [ʔiˈɾɒn] ('Iran'), and foreign nouns (both common and proper), like the Spanish surname Beltran [belˈtɾɒn], which are pronounced as written. A few words written as /ɒm/ are pronounced [um], especially forms of the verb /ɒmædæn/ ('to come').
- In the Tehrani accent, the unstressed direct object suffix marker /ɾɒ/ is pronounced /ɾo/, or /o/ after a consonant.
- The stems of many verbs have a short colloquial form, especially /æst/ ('he/she is'), which is colloquially shortened to /e/ after a consonant or /je/ after a vowel.
- The 2nd and 3rd person plural verb subject suffixes, written /-id/ and /-ænd/ respectively, are pronounced [-in] and [-æn].
- Many frequently-occurring verbs are shortened, such as /mixɒːhæm/ ('I want') → [mixɒm], and /miɾævæm/ ('I go'_ → [miɾæm].
|Broad IPA Transcription||Native orthography||Gloss|
|/jek ˈɾuz ˈbɒde ʃoˈmɒl væ xorˈʃid bɒhæm dæʔˈvɒ ˈmikæɾdænd ke koˈdɒm jek ɢæviˈtæɾ æst/||
یک روز باد شمال و خورشید با هم دعوا میکردند که کدام یک قویتر است
|[One day] the North Wind and the Sun were disputing which was the stronger.|
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- Jahani, Carina (2005). "The Glottal Plosive: A Phoneme in Spoken Modern Persian or Not?". In Éva Ágnes Csató, Bo Isaksson, and Carina Jahani. Linguistic Convergence and Areal Diffusion: Case studies from Iranian, Semitic and Turkic. London: RoutledgeCurzon. pp. 79–96. ISBN 0-415-30804-6.
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