Thread: Piglatin program that prints no words out:(

I am a high school student in a beginners programming class and I have to create a pig latin program that takes the first consonants and puts them to the end of the word and ads "ay". I really don't know what I'm doing and my code is printing out no words and I've tried to fix it and I don't know what the issue is because no error codes are showing up. I can't use arrays and can only use for loops, if/else, and while.

import java.util.Scanner;
public class PigLatin
{
   public static void main(String args[])
   {
       Scanner input = new Scanner(System.in);
       System.out.println("Enter a phrase: ");
       String phrase = input.nextLine();
       System.out.println("Here is your phrase in pig latin: " + sepword(phrase));
   }
   public static String sepword(String phrase)
   {
       phrase = phrase + " ";
       String sentence = "";
       for (int i = 0; i < phrase.length(); i++)
       {
           String word = "";
           if (phrase.charAt(i) == ' ')
           {
              word = phrase.substring(0, i);
              if (word.charAt(0) == 'a' ||
                  word.charAt(0) == 'i' ||
                  word.charAt(0) == 'o' ||
                  word.charAt(0) == 'u' ||
                  word.charAt(0) == 'e')
                  {
                      sentence+=vowel(word);
                  }
               else
               {
                   sentence+=consonant(word);
               }
           }
           phrase = phrase.substring(i+1);
       }
       return sentence;
   }
   public static String vowel(String word)
   {
       return word+"-ay ";
   }
   public static String consonant(String word)
   {
       for (int i = 0; i < word.length(); i++)
       {
           String firstletters = "";
           while (word.charAt(i) != 'a' ||
                  word.charAt(i) != 'i' ||
                  word.charAt(i) != 'o' ||
                  word.charAt(i) != 'u' ||
                  word.charAt(i) != 'e')
                  {
                     firstletters+=word.charAt(i);
                  }
                  word = word.substring(i)+"-"+firstletters+"ay ";
       }
       return word;
   }
}

import java.util.Scanner;
public class PigLatin_Rider
{
   public static void main(String args[])
   {
       Scanner input = new Scanner(System.in);
       System.out.println("Enter a phrase: ");
       String phrase = input.nextLine();
       String piglatin = sepword(phrase);
       System.out.println("Here is your phrase in pig latin: " + piglatin);
   }
   public static String sepword(String phrase) //separate words and then determine whether they begin with vowels or consonants
   {
       phrase = phrase + " "; //add a space to original phrase to catch the last word
       String sentence = ""; 
       for (int i = 0; i < phrase.length(); i++)
       {
           String word = "";
           if (phrase.charAt(i) == ' ')
           {
              word = phrase.substring(0, i); 
              if (word.charAt(0) == 'a' ||  //check if the word begins with a vowel; if it does, call on vowel method
                  word.charAt(0) == 'i' ||
                  word.charAt(0) == 'o' ||
                  word.charAt(0) == 'u' ||
                  word.charAt(0) == 'e')
                  {
                      sentence+=vowel(word);
                  }
               else //if word doesn't begin with vowel, call on consonant method
               {
                   sentence+=consonant(word);
               }
           }
           phrase = phrase.substring(i+1); //reset phrase to get rid of the word I just "piglatin"d
       }
       return sentence;
   }
   public static String vowel(String word) //adds "ay" to the end of a word that starts with vowel
   {
       return word+"-ay ";
   }
   public static String consonant(String word)
   {
       for (int i = 0; i < word.length(); i++)
       {
           String firstletters = ""; 
           while (word.charAt(i) != 'a' ||  //goes through while loop until it finds a consonant, then adds the string of vowels after the consonant
                  word.charAt(i) != 'i' ||
                  word.charAt(i) != 'o' ||
                  word.charAt(i) != 'u' ||
                  word.charAt(i) != 'e')
                  {
                     firstletters+=word.charAt(i);
                  }
                  word = word.substring(i)+"-"+firstletters+"ay ";
       }
       return word;
   }
}