array( 'access', 'advice', 'aircraft', 'art', 'baggage', 'bison', 'dances', 'deer', 'equipment', 'fish', 'fuel', 'furniture', 'heat', 'honey', 'homework', 'impatience', 'information', 'knowledge', 'luggage', 'media', 'money', 'moose', 'music', 'news', 'patience', 'progress', 'pollution', 'research', 'rice', 'salmon', 'sand', 'series', 'sheep', 'sms', 'spam', 'species', 'staff', 'swine', 'toothpaste', 'traffic', 'understanding', 'water', 'weather', 'work', ), 'irregular' => array( 'appendix' => 'appendices', 'cactus' => 'cacti', 'calf' => 'calves', 'child' => 'children', 'crisis' => 'crises', 'criterion' => 'criteria', 'curriculum' => 'curricula', 'diagnosis' => 'diagnoses', 'elf' => 'elves', 'ellipsis' => 'ellipses', 'foot' => 'feet', 'goose' => 'geese', 'hero' => 'heroes', 'hoof' => 'hooves', 'hypothesis' => 'hypotheses', 'is' => 'are', 'knife' => 'knives', 'leaf' => 'leaves', 'life' => 'lives', 'loaf' => 'loaves', 'man' => 'men', 'mouse' => 'mice', 'nucleus' => 'nuclei', 'oasis' => 'oases', 'octopus' => 'octopi', 'ox' => 'oxen', 'paralysis' => 'paralyses', 'parenthesis' => 'parentheses', 'person' => 'people', 'phenomenon' => 'phenomena', 'potato' => 'potatoes', 'quiz' => 'quizzes', 'radius' => 'radii', 'scarf' => 'scarves', 'stimulus' => 'stimuli', 'syllabus' => 'syllabi', 'synthesis' => 'syntheses', 'thief' => 'thieves', 'tooth' => 'teeth', 'was' => 'were', 'wharf' => 'wharves', 'wife' => 'wives', 'woman' => 'women', 'release' => 'releases', ), );