public String getPluralForm()
	 {
	     // TODO: Complete this method
	     // If the word ends in y preceded by a consonant you take away the y and add ies.
	     // If the word ends in y preceded by a vowel, you just add an s.
	     // You add an es when a word ends in o, or s, or sh, or ch.
	     // In all the other case just add an s.
	     // you can use the
	     //  isVowel
	     //  isConsonant
	     //  is
	     // methods from below.
	     int letterLen = letters.length();
	     String lastLet = letters.substring(letterLen-1);
	     if (lastLet.equals("y") && isConsonant(letterLen-2))
	     {
	         String stringYC = letters.substring(0, letterLen-1) + "ies";
	         return stringYC;
	     }
	     else if (lastLet.equals("y") && isVowel(letterLen-2))
	     {
	         String stringYV = letters + "s";
	         return stringYV;
	     }
	     else if (lastLet.equals("o") || lastLet.equals("s")
	              || letters.substring(letterLen-2, letterLen).equals("sh")
	              || letters.substring(letterLen-2, letterLen).equals("ch"))
	     {
	         String stringOS = letters + "es";
	         return stringOS;
	     }
	     else
	     {
	         String stringOT = letters + "s";
	         return stringOT;
	     }
	 }