Nouns of Foreign Origin in English

In English there is a group of nouns with very unusual plural forms. This group consists mainly of nouns of foreign origin especially of Latin and Greek. Below you can find a list with some examples of such nouns.

Singular	Plural
analysis	analyses
antenna	antennae / antennas
appendix	appendixes/appendices
axis	axes
bacterium	bacteria
basis	bases
bureau	bureaux
cactus	cactuses/cacti
codex	codices
criterion	criteria
crisis	crises
curriculum	curricula
datum	data
diagnosis	diagnoses
focus	focuses/foci
formula	formulae / formulas
fungus	fungi
index	indexes/indices
kibbutz	kibbutzim
larva	larvae
medium	mediums/media
nucleus	nuclei
oasis	oases
octopus	octopuses/octopi
phenomenon	phenomena
stimulus	stimuli
syllabus	syllabuses/syllabi
tempo	tempi
terminus	termini / terminuses
thesis	theses