Persian Morphology
Word Formation and Derivation

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 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)