Appendix II: Unusual plural forms

SingularPlural
addendumaddenda
agendaagendas
appendixappendices
basisbases
bureaubureaus
campuscampuses
consortiumconsortia
corpscorps
criterioncriteria
curriculumcurricula
formulaformulas
indexindexes, indices
maximummaximums
mediummedia, mediums
memorandummemoranda
millenniummillennia
phenomenonphenomena
pluspluses
practicumpracticums
premiumpremiums
quantumquanta
referendumreferendums
stimulusstimuli
syllabussyllabuses
thesistheses