600. (1.) Stems of the first class have one or two syllables; there are
four of them: #rēs#, _thing_, #spēs#, _hope_, #diēs#, _day_, and
#fidēs#, _faith_.
Of this class, #rēs# and #diēs# have a plural throughout; #spēs# has
only the nominative and accusative plural, and #fidēs# has no plural.