Persian suffix i (ی) is a versatile suffix. It can convert a noun into an adjective and vice versa. If the word ends in the vowel e, the suffix i typically changes to -gi. After other vowels, it changes to -yi.
Nouns to adjectives
| Word | Derivation |
|---|---|
| ایران Irân Iran |
ایرانی Irâni Iranian |
| آمریکا Âmrikâ America |
آمریکایی Âmrikâyi American |
| مرکز markaz center |
مرکزی markazi central |
| دین din relegion |
دینی dini religious |
| هفته hafte week |
هفتگی haftegi weekly |
| شمال shomâl north |
شمالی shomâli northern |
| قهوه ghahve coffee |
قهوه‌ای ghahvei brown |
Adjectives to nouns
| Word | Derivation |
|---|---|
| سرد sard cold |
سردی sardi coldness |
| زیبا zibâ beautiful |
زیبایی zibâyi beauty |
| خوب khub good |
خوبی khubi goodness |
| خسته khaste tired |
خستگی khastegi tiredness |
| زنده zende alive, live |
زندگی zendegi life |
Infinitives to adjectives
The suffix i can convert an infinitive to an adjective. The resulting derivation means "to be worth", suitable for being", "able to be", etc. depending on the context. Its role is comparable to English suffixes "-ible" and "-able".
| Infinitive | Derivation |
|---|---|
| دیدن didan to see |
دیدنی didani worth seeing |
| خواندن khwândan to read |
خواندنی khwândani worth reading |
| شنیدن shenidan to hear |
شنیدنی shenidani worth hearing |
| شستن shostan to wash |
شستنی shostani washable |
| دوست داشتن dust dâshtan to love |
دوست‌داشتنی dustdâshtani loveable |
| به یاد ماندن be yâd mândan to remember |
به‌یادماندنی beyâdmândani memorable |
| باور کردن bâvar kardan to believe |
باورکردنی bâvarkardani believable |
| باور نکردن bâvar nakardan not to believe |
باورنکردنی bâvarnakardani unbelievable |
Historical notes
In Middle Persian, the suffix -îh was used to derive a noun from an adjective and the suffix -îg was used to derive an adjective from a noun. Both of these suffixes became -î in New Persian. The suffix -îg is cognate with Latin -icus which is used as -ic in English (e.g. basic, acidic)
In transition from Middle Persian to New Persian, words that ended in -ag, lost their final -g and became -a. This ending has further evolved and has become -e in the standard dialect of Iran.
| Middle Persian | Modern Persian | Meaning |
|---|---|---|
| khânag | khâne | house |
| haftag | hafte | week |
In cases where -ag has accepted a suffix, its -g has been preserved. That is why when a suffix like -i is added to these words, their historical -g reappears.
| Word | Derivation |
|---|---|
| هفته hafte week |
هفتگی haftegi weekly |
| خسته khaste tired |
خستگی khastegi tiredness |
Words that end in -e and did not exist in Middle Persian, simply take -i:
| Word | Derivation |
|---|---|
| قهوه ghahve coffee |
قهوه‌ای ghahvei brown |
| نقره noghre silver (noun) |
نقره‌ای noghrei silver (adjective) |