def plural_rules
[
[/^(ox)$/i, '\1\2en'],
[/([m|l])ouse$/i, '\1ice'],
[/(matr|vert)ix|ex$/i, '\1ices'],
[/(x|ch|ss|sh)$/i, '\1es'],
[/([^aeiouy]|qu)ies$/i, '\1y'],
[/([^aeiouy]|qu)y$/i, '\1ies'],
[/(hive)$/i, '\1s'],
[/(?:([^f])fe|([lr])f)$/i, '\1\2ves'],
[/sis$/i, 'ses'],
[/([ti])um$/i, '\1a'],
[/(p)erson$/i, '\1eople'],
[/(m)an$/i, '\1en'],
[/(c)hild$/i, '\1hildren'],
[/(buffal|tomat)o$/i, '\1\2oes'],
[/(bu)s$/i, '\1\2ses'],
[/(alias)/i, '\1es'],
[/(octop|vir)us$/i, '\1i'],
[/(ax|cri|test)is$/i, '\1es'],
[/s$/i, 's'],
[/$/, 's']
]
end