Make the nouns plural. Phenomenon, crisis, stimulus, index, antenna, formula, datum, nucleus, criterion, analysis, apparatus, basis, appendix, tableau, radius, miasma, hypothe

Phenomena, crises, stimuli, indexes or indices, antennae or antennas, formulas or formulae, data, nuclei, criteria, analyses, apparatus or apparatuses, bases, appendixes or appendices, tableaux, radii or radiuses, miasmas, hypotheses, axes, genera, vertebrae.