C# Pluralize method

gistfile1.cs

/// <summary>
/// Attempts to pluralize the specified text according to the rules of the English language.
/// </summary>
/// <remarks>
/// This function attempts to pluralize as many words as practical by following these rules:
/// <list type="bullet">
///		<item><description>Words that don't follow any rules (e.g. "mouse" becomes "mice") are returned from a dictionary.</description></item>
///		<item><description>Words that end with "y" (but not with a vowel preceding the y) are pluralized by replacing the "y" with "ies".</description></item>
///		<item><description>Words that end with "us", "ss", "x", "ch" or "sh" are pluralized by adding "es" to the end of the text.</description></item>
///		<item><description>Words that end with "f" or "fe" are pluralized by replacing the "f(e)" with "ves".</description></item>
///	</list>
/// </remarks>
/// <param name="text">The text to pluralize.</param>
/// <param name="number">If number is 1, the text is not pluralized; otherwise, the text is pluralized.</param>
/// <returns>A string that consists of the text in its pluralized form.</returns>
public static string Pluralize(string text, int number = 2)
{
	if (number == 1)
	{
		return text;
	}
	else
	{
		// Create a dictionary of exceptions that have to be checked first
		// This is very much not an exhaustive list!
		Dictionary<string, string> exceptions = new Dictionary<string, string>() {
				{ "man", "men" },
				{ "woman", "women" },
				{ "child", "children" },
				{ "tooth", "teeth" },
				{ "foot", "feet" },
				{ "mouse", "mice" },
				{ "belief", "beliefs" } };

		if (exceptions.ContainsKey(text.ToLowerInvariant()))
		{
			return exceptions[text.ToLowerInvariant()];
		}
		else if (text.EndsWith("y", StringComparison.OrdinalIgnoreCase) &&
			!text.EndsWith("ay", StringComparison.OrdinalIgnoreCase) &&
			!text.EndsWith("ey", StringComparison.OrdinalIgnoreCase) &&
			!text.EndsWith("iy", StringComparison.OrdinalIgnoreCase) &&
			!text.EndsWith("oy", StringComparison.OrdinalIgnoreCase) &&
			!text.EndsWith("uy", StringComparison.OrdinalIgnoreCase))
		{
			return text.Substring(0, text.Length - 1) + "ies";
		}
		else if (text.EndsWith("us", StringComparison.InvariantCultureIgnoreCase))
		{
			// http://en.wikipedia.org/wiki/Plural_form_of_words_ending_in_-us
			return text + "es";
		}
		else if (text.EndsWith("ss", StringComparison.InvariantCultureIgnoreCase))
		{
			return text + "es";
		}
		else if (text.EndsWith("s", StringComparison.InvariantCultureIgnoreCase))
		{
			return text;
		}
		else if (text.EndsWith("x", StringComparison.InvariantCultureIgnoreCase) ||
			text.EndsWith("ch", StringComparison.InvariantCultureIgnoreCase) ||
			text.EndsWith("sh", StringComparison.InvariantCultureIgnoreCase))
		{
			return text + "es";
		}
		else if (text.EndsWith("f", StringComparison.InvariantCultureIgnoreCase) && text.Length > 1)
		{
			return text.Substring(0, text.Length - 1) + "ves";
		}
		else if (text.EndsWith("fe", StringComparison.InvariantCultureIgnoreCase) && text.Length > 2)
		{
			return text.Substring(0, text.Length - 2) + "ves";
		}
		else
		{
			return text + "s";
		}
	}
}