An example of oi used as an interjection is in the following sentences: "Oi! I forgot my wallet at home!" which means "Oh no! I forgot my wallet at home!"
Origin of oi
- From the Ancient Greek -οι (-oi), the second-declension masculine nominative plural case ending — the plural form of -ος (-os); compare the equivalents of the Latin second declension (-us → -ī), with which the Grecian case endings are usually substituted in English words, especially in the plural.