Since we are speaking... well, writing... English, a foreign word could be from any other language. So it depends on what language you are talking about. For example "Küche" means kitchen in German and the plural is "Küchen." In Italian it would be "cucina" singular and "cucine" plural. Other languages have their own words for kitchen along with other things.
foreign plural:Antennae English Plural:Antennas
The plural of foramen is foramina.
culinae
The word is a utensil, as in a kitchen utensil. Plural is utensils.
The plural form of the noun 'bandit' is bandits.The noun 'bandits' is a 'regular plural' form, a word that forms its plural by adding an 's' or an 'es' to the end of the word.
The plural forms for cactus are cacti or cactuses, both are accepted.
The plural form of the noun 'crux' is cruxes.The plural noun 'cruxes' is a 'regular plural' form, a word that forms its plural by adding an 's' or an 'es' to the end of the word.
The plural form of apparatus is apparatuses. It has no foreign plural.
Forum---Plural Form Forums,Foreign Plural Form Forumina
The foreign plural of "prospectus" is "prospectuses."
The foreign plural of addendum is "addenda."
Well, the English Plural is momentums and the Foreign Plural is momenta!