Alumnus vs. Alumni
The English language includes many words that have origins in other languages. One of these other languages is Latin. There are many words that we use today (radius, octopus, cactus) that are derived from Latin. In addition, we continue to use Latin words in much medical and legal jargon. This use of Latin nouns is tricky, however, when we start to make these words plural!
Alumnus is a noun that refers to a person who graduated from or attended a particular school. This is the singular form of the noun.
1. I am an alumnus of Florida State University.
2. Is President Obama an alumnus of an Ivy League university?
3. The superintendent of the school system is also an alumnus of the school system.
Alumni is the plural form of alumnus. It refers to more than one graduate of a particular school. It can also be used as an adjective.
1. The alumni association is having a barbecue before the homecoming game.
2. Many of the alumni of the university return to attend football games each fall.
3. Just because I am an alumni of the university does not mean that I want to give a donation of money to the school.
Alumni is the plural of alumnus. This is an example of an irregular plural form in English, where the "us" at the end of the word is changed to an "i" to make the plural. This occurs in specific nouns that are derived from the Latin (cactus-cacti; radius-radii).
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