SpellCheck Challenge

/*
 * http://www.reddit.com/r/CS_Questions/comments/maz1l/spellcheck/
 * http://en.wikipedia.org/wiki/Lama_%28genus%29
 *
 *
 */

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.IO;

namespace Challenges
{
    class Program
    {
        static Dictionary<String, List<String>> words = new Dictionary<String, List<String>>();

        static void Main(string[] args)
        {
            String word = "lAmaa";

            LoadTxt();

            //PrintWords();

            if (SpellCheck(word))
            {
                PrintSuggestions(word);
            }
        }

        private static void PrintSuggestions(String word)
        {
            foreach (var item in Suggestions(word))
            {
                Console.WriteLine(item);
            }
        }

        private static void PrintWords()
        {

            foreach (var pair in words)
            {
                //if (pair.Value.Count<2)
                //    continue;

                Console.Write(pair.Key +": ("+ pair.Value.Count +") ");
                foreach (var value in pair.Value)
                {
                    Console.Write(value + " ");
                }
                Console.WriteLine();
            }
        }

        private static void LoadTxt()
        {
            String txt = File.ReadAllText("lama.txt");

            txt = txt.
                Replace("(", " ").
                Replace(")", " ").
                Replace("[", " ").
                Replace("]", " ").
                Replace(";", " ").
                Replace(",", " ").
                Replace(":", " ").
                Replace(".", " ").
                Replace("-", " ").
                Replace("_", " ").
                Replace("\\", " ").
                Replace("/", " ").
                Replace("&", " ").
                Replace("%", " ").
                Replace("$", " ").
                Replace("§", " ").
                Replace("!", " ").
                Replace("=", " ").
                Replace("?", " ").
                Replace("+", " ").
                Replace("*", " ").
                Replace("#", " ").
                Replace("\n", " ").
                Replace("\r", " ").
                Replace("\t", " ").
                Replace("  ", " ");

            String[] list = txt.Split(' ');

            for (int i = 0; i < list.Length; i++)
            {
                AddWord(list[i]);
            }

        }

        private static void AddWord(string word)
        {
            if (string.IsNullOrEmpty(word))
            {
                return;
            }

            String key = ReduceWord(word);

            if (words.ContainsKey(key))
            {
                if (!words[key].Contains(word))
                    words[key].Add(word);
            }
            else
            {
                words.Add(key, new List<String>() { word });
            }

        }

        private static bool SpellCheck(String word)
        {
            word = ReduceWord(word);

            return words.ContainsKey(word);
        }

        private static String[] Suggestions(String word)
        {
            if (String.IsNullOrEmpty(word))
            {
                return new String[0];
            }

            String key = ReduceWord(word);

            if (words.ContainsKey(key))
            {
                return words[key].ToArray();
            }

            return new String[0];
        }

        private static String ReduceWord(String word)
        {
            // 1. condtion: Capitalization
            word = word.ToLower();

            // 2. condtion: Vowels
            word = word.Replace("a", "u").Replace("e", "u").Replace("i", "u").Replace("o", "u");

            // 3. condtion: Doubles
            foreach (var ch in "abcdefghijklmnopqrstuvwxyz")
            {
                word = word.Replace(ch.ToString() + ch.ToString(), ch.ToString());
            }

            return word;
        }
    }
}