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: with آی at word initial and with ای in all other positions.

WordPronunciationMeaning
آینهâynemirror
زایمانzâymânchildbirth
چایchâytea

Diphthong “ey”

The diphthong ey is made up of the vowels e and i. The vowel e is partially marked and consequently, 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.

WordPronunciationMeaning
ای / اِی / اِیْeyo! (vocative)
ایوان / اِیوان / اِیْوانeyvânbalcony
میدان / مِیدان / مِیْدانmeydânsquare (street)
می / مِی / مِیْmeywine

Diphthong “oy”

The diphthong oy is made up of the vowels o and i. Both of these vowels are marked and consequently, this diphthong is always marked in writing: 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.

WordPronunciationMeaning
خوی / خُوی / خُویْkhoysweat (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: with اوی at word initial and with وی in all other positions. Additionally, the diacritic ساکن (sâken) can be place over ی.

WordPronunciationMeaning
روی / رویْruyzinc; 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: with او at word initial and with و in all other positions. The diacritic پیش (pish) can be placed over the preceding consonant.

WordPronunciationMeaning
اوجowjhighest point, culmination
موزmowzbanana
نوnownew

Summary

The following table summarizes diphthong marking in different word positions. The diacritics zir (/e/), zebar (/a/), pish (/o/) and sâken as well as the letters ا,‎ ی and و are used to indicate diphthongs.

DiphthongWord InitialWord MedialWord Final
âyآیایای
eyاِیــِـ یــِـ ی
oyاُیویوی
uyاویویوی
owاُوُوُو