Kenneth G. Wilson (1923–). The Columbia Guide to Standard American English. 1993.
memento (n.)
is pronounced me-MEN-to and means “a reminder, a souvenir”; it has two plurals: mementos and mementoes. To mispronounce or misspell it with an o in the first syllable is to be guilty of a shibboleth, even though some dictionaries report that momento has been used enough to make it a variant. See PLURALS OF NOUNS ENDING IN -O.
