Persian diphthongs are combinations of a vowel with either i or u. Therefore, their marking is similar to the marking pattern of their constituents.

Diphthong “ây”

The diphthong ây is made up of the vowels â and i. Both of these vowels are always marked. Thus, the diphthong ây is always marked in writing. The diphthong ây is marked with آی at word initial and with ای in all other positions.

Word Pronunciation Meaning
آینه âyne mirror
چای chây tea

Diphthong “ey”

The diphthong ey is made up of the vowels e and i. The vowel e is partially marked and consequently, the diphthong ey is partially marked in writing. The diphthong ey is marked with ای at word initial and with ی in all other positions. To denote ey clearly, the diacritic زیر (zir) can be placed below the preceding consonant and the diacritic ساکن (sâken) over the ی.

Word Pronunciation Meaning
ای
اِی
اِیْ
ey o! (vocative)
ایوان
اِیوان
اِیْوان
eyvân balcony
میدان
مِیدان
مِیْدان
meydân square (street)
می
مِی
مِیْ
mey wine

Diphthong “oy”

The diphthong oy is made up of the vowels o and i. Both of these vowels are marked and consequently, the diphthong oy is always marked in writing. The diphthong oy is marked with ای at word initial and with وی in all other positions. To denote oy clearly, the diacritic پیش (pish) can be placed over the preceding consonant and the diacritic ساکن (sâken) over the ی.

Word Pronunciation Meaning
خوی
خُوی
خُویْ
khoy sweat (obsolete); name of a city

Diphthong “uy”

The diphthong uy is made up of the vowels u and i. Both of these vowels are always marked. Thus, the diphthong uy is always marked in writing. The diphthong uy is marked with اوی at word initial and with وی in all other positions. Additionally, the diacritic ساکن (sâken) can be place over ی.

Word Pronunciation Meaning
روی
رویْ
ruy zinc; face

Diphthong “ow”

The diphthong ow is made up of the vowels o and u. Both of these vowels are marked and consequently, the diphthong ow is always marked in writing. The diphthong ow is marked with او at word initial and with و in all other positions. The diacritic پیش (pish) can be placed over the preceding consonant.

Word Pronunciation Meaning
اوج owj highest point, culmination
موز mowz banana
نو now new

Summary

Diphthong Word Initial Word Medial Word Final
ây آی ای ای
ey اِی ـِ ی ـِ ی
oy اُی وی وی
uy اوی وی وی
ow اُو ُو ُو