Etymology A conflation of the following suffixes: * For Semitic-speaking places, from the Arabic ـِيّ (-iyy) (nisba suffix) and from Hebrew ־י (-i), both sharing a common Semitic root. * For Indo-Iranian-speaking places, from Persian ـی (-ī) and Hindustani Hindi -ई (-ī) / Urdu ـی (-ī). In English, productive since the 19th century.
1
Morpheme Used to form adjectives, nouns, demonyms (describing people of a particular city, region or country) or genonyms (describing people of a particular tribe, clan or family) and the language spoken by these people.
Morpheme Forms an alternative plural ending for various words borrowed from Latin that end in ⟨us⟩ in the singular.
focus + -i → foci
radius + -i → radii
2
Morpheme, Nonstandard, Proscribed, Sometimes Forms an alternative plural ending for various words that end in ⟨us⟩ in the singular, despite not being borrowed from Latin.
platypus + -i → platypi
amogus + -i → amogi
-i
suffix
Etymology From Italian -i (masculine plural), from Latin -ī (see etymology 2).
1
Morpheme Forms an alternative plural ending for words borrowed from Italian that end in ⟨o⟩ or ⟨e⟩ in the singular.