JSFiddle - React, Tailwind, and code Playground

HTML

<div id="demo"></div>

JavaScript

String.prototype.plural = function(revert){
    
    var plural = {
        '(quiz)$'               : "$1zes",
        '^(ox)$'                : "$1en",
        '([m|l])ouse$'          : "$1ice",
        '(matr|vert|ind)ix|ex$' : "$1ices",
        '(x|ch|ss|sh)$'         : "$1es",
        '([^aeiouy]|qu)y$'      : "$1ies",
        '(hive)$'               : "$1s",
        '(?:([^f])fe|([lr])f)$' : "$1$2ves",
        '(shea|lea|loa|thie)f$' : "$1ves",
        'sis$'                  : "ses",
        '([ti])um$'             : "$1a",
        '(tomat|potat|ech|her|vet)o$': "$1oes",
        '(bu)s$'                : "$1ses",
        '(alias)$'              : "$1es",
        '(octop)us$'            : "$1i",
        '(ax|test)is$'          : "$1es",
        '(us)$'                 : "$1es",
        '([^s]+)$'              : "$1s"
    };
    
    var singular = {
        '(quiz)zes$'             : "$1",
        '(matr)ices$'            : "$1ix",
        '(vert|ind)ices$'        : "$1ex",
        '^(ox)en$'               : "$1",
        '(alias)es$'             : "$1",
        '(octop|vir)i$'          : "$1us",
        '(cris|ax|test)es$'      : "$1is",
        '(shoe)s$'               : "$1",
        '(o)es$'                 : "$1",
        '(bus)es$'               : "$1",
        '([m|l])ice$'            : "$1ouse",
        '(x|ch|ss|sh)es$'        : "$1",
        '(m)ovies$'              : "$1ovie",
        '(s)eries$'              : "$1eries",
        '([^aeiouy]|qu)ies$'     : "$1y",
        '([lr])ves$'             : "$1f",
        '(tive)s$'               : "$1",
        '(hive)s$'               : "$1",
        '(li|wi|kni)ves$'        : "$1fe",
        '(shea|loa|lea|thie)ves$': "$1f",
        '(^analy)ses$'           : "$1sis",
        '((a)naly|(b)a|(d)iagno|(p)arenthe|(p)rogno|(s)ynop|(t)he)ses$': "$1$2sis",        
        '([ti])a$'               : "$1um",
        '(n)ews$'                : "$1ews",
        '(h|bl)ouses$'           : "$1ouse",
       ...