namespace ConsoleApplication1
public static void Main(string[] args)
CheckHi("The child wanted to play in the mud");
CheckHi("Hector had a hip problem");
CheckHi("He said, 'Hi, how are you?'");
private static void CheckHi(string sentence)
var punctuation = sentence.Where(Char.IsPunctuation).Distinct().ToArray();
var words = sentence.Split().Select(x => x.Trim(punctuation));
var containsHi = words.Contains("hi", StringComparer.OrdinalIgnoreCase);
Console.WriteLine("{0}: {1}", containsHi, sentence);