Some nouns adopted from foreign languages still retain their original plural forms. Some of these take the English plural also.
+Direction+.—Learn to form the following plurals:—
Analysis, analyses; antithesis, antitheses; appendix, appendices or appendixes; automaton, automata or automatons; axis, axes; bandit, banditti or bandits; basis, bases; beau, beaux or beaus; cherub, cherubim or cherubs; crisis, crises; datum, data; ellipsis, ellipses; erratum, errata; focus, foci: fungus, fungi or funguses; genus, genera; hypothesis, hypotheses; ignis fatuus, ignes fatui; madame, mesdames; magus, magi; memorandum, memoranda or memorandums; monsieur, messieurs; nebula, nebulae; oasis, oases; parenthesis, parentheses; phenomenon, phenomena; radius, radii or radiuses; seraph, seraphim or seraphs; stratum, strata; synopsis, synopses; terminus, termini; vertebra, vertebrae; vortex, vortices or vortexes.
The following compound nouns, in which the principal word stands first, vary the first word; as, sons-in-law.
+Direction+.—Form the plural of the following words:—
Aid-de-camp, attorney-at-law, billet-doux, [Footnote: Plural, billets-doux, pronounced bil'-la:-doo:z ] commander-in-chief, court-martial, cousin-german, father-in-law, hanger-on, man-of-war.
The following, and most compounds, vary the last word; as, pailfuls, gentle_men_. [Footnote: Pails full is not a compound. This expression denotes a number of pails, each full.]
+Direction+.—Form the plural of each of the following nouns:—
Courtyard, dormouse, Englishman, fellow-servant, fisherman, Frenchman, forget-me-not, goose-quill, handful, maid-servant, man-trap, mouthful, pianoforte, portemonnaie, spoonful, stepson, tete-a-tete, tooth-brush.
The following nouns (except Norman) are not compounds of man—add s to all.