Generate a Random Pronouncable Word

RandomWord.cs

    public static class RandomWord
    {
        private static List<string> Consonants = new List<string>() {
                // single consonants. without 'q' since it's often awkward in words
		        "b", "c", "d", "f", "g", "h", "j", "k", "l", "m",
                "n", "p", "r", "s", "t", "v", "w", "x", "z",

		        // possible combinations excluding those which cannot start a word
		        "pt", "gl", "gr", "ch", "ph", "ps", "sh", "st", "th", "wh",
        };

        private static List<string> ConsonantsSuffixes = new List<string>() {
                // these consonants are to be avoided in the beginning of words
                "ck", "cm", "dr", "ds", "ft", "gh", "gn", "kr", "ks", "ls",
                "lt", "lr", "mp", "mt", "ms", "ng", "ns", "rd", "rg", "rs",
                "rt", "ss", "ts", "tch",
        };

        private static List<string> Vowels = new List<string>() {
                // single vowels
		        "a", "e", "i", "o", "u", "y", 
		        // vowel combinations your language allows
		        "ee", "oa", "oo",
        };

        private enum Sound {
            Consonant,
            Vowel
        };

        public static string Generate(int length)
        {
            var currentSound = new[] { Sound.Consonant, Sound.Vowel }.Shuffle()[0];
            var currentWord = "";

            while (currentWord.Length < length) {
                var rnd = "";

                // random sign from either cons or vows,
                // after the first letter, use every consonant combo
                switch (currentSound) {
                    case Sound.Consonant:
                        rnd = currentWord.Length > 1 ?
                                Consonants.Concat(ConsonantsSuffixes).ToList().Shuffle()[0] :
                                Consonants.Shuffle()[0];
                        break;
                    case Sound.Vowel:
                        rnd = Vowels.Shuffle()[0];
                        break;
                }

                // check if random sign fits in word length
                if (currentWord.Length + rnd.Length <= length) {
                    currentWord += rnd;

                    // alternate sounds
                    currentSound = currentSound == Sound.Consonant ?
                                     Sound.Vowel : Sound.Consonant;
                }
            }

            return currentWord;
        }

    }

    public static class Helpers
    {
        public static T[] Shuffle<T>(this T[] list) => Shuffle(list.ToList()).ToArray();
        public static IList<T> Shuffle<T>(this IList<T> list)
        {
            var provider = new RNGCryptoServiceProvider();
            var n = list.Count;
            while (n > 1) {
                var box = new byte[1];
                do
                    provider.GetBytes(box);
                while (!(box[0] < n * (byte.MaxValue / n)));
                var k = (box[0] % n);
                n--;
                var value = list[k];
                list[k] = list[n];
                list[n] = value;
            }

            return list;
        }
    }