private void Form1_Load(object sender, EventArgs e)
{
  sre = new SpeechRecognitionEngine(new System.Globalization.CultureInfo("en-US"));
  sre.SetInputToDefaultAudioDevice();

  // Create an SrgsDocument instance and compile it.
  SrgsDocument srgsDoc = new SrgsDocument();
  srgsDoc = CreateGrammar();
  CompileGrammar(srgsDoc, @"C:\test\AirportCodes.cfg");
  Grammar g = new Grammar(@"C:\test\AirportCodes.cfg", "flightBooker");

  // Load the grammar to the SpeechRecognitionEngine.
  sre.LoadGrammar(g);

  // Attach a handler for the SpeechRecognized event.
  sre.SpeechRecognized += 
    new EventHandler<SpeechRecognizedEventArgs>(sre_SpeechRecognized);

  // Start asynchronous recognition.
  sre.RecognizeAsync();
  Console.WriteLine("Starting asynchronous recognition...\n");

  // Keep the console window open.
  Console.ReadLine();
}

void sre_SpeechRecognized(object sender, SpeechRecognizedEventArgs e)
{
  string recoString = e.Result.Text;
  string departCity = e.Result.Semantics["LeavingFrom"].Value.ToString();
  string arriveCity = e.Result.Semantics["GoingTo"].Value.ToString(); 
  
  MessageBox.Show(String.Format("Recognized phrase: {0}\nDeparting from: {1}\nArriving at: {2}", recoString, departCity, arriveCity));
}

private SrgsDocument CreateGrammar()
{
  SrgsDocument srgsDoc = new SrgsDocument();

  // Create a rule for cities, assign a semantic value to each city.
  SrgsRule cities = new SrgsRule("flightCities");
  SrgsItem chi = new SrgsItem("Chicago");
  chi.Add(new SrgsSemanticInterpretationTag("$ = \"ORD\";"));
  SrgsItem bos = new SrgsItem("Boston");
  bos.Add(new SrgsSemanticInterpretationTag("$ = \"BOS\";"));
  SrgsItem mia = new SrgsItem("Miami");
  mia.Add(new SrgsSemanticInterpretationTag("$ = \"MIA\";"));
  SrgsItem dal = new SrgsItem("Dallas");
  dal.Add(new SrgsSemanticInterpretationTag("$ = \"DFW\";"));
  SrgsOneOf airports = new SrgsOneOf(chi, bos, mia, dal);
  cities.Add(airports);
  cities.Scope = SrgsRuleScope.Private;

  // Create a rule reference to the rule for cities.
  SrgsRuleRef cityRef = new SrgsRuleRef(cities);

  // Create the root rule for the grammar.
  SrgsRule bookFlight = new SrgsRule("flightBooker");
  bookFlight.Add(new SrgsItem("I want to fly from"));
  bookFlight.Add(cityRef);
  bookFlight.Add(new SrgsSemanticInterpretationTag("$.LeavingFrom=$$;"));
  bookFlight.Add(new SrgsItem("to"));
  bookFlight.Add(cityRef);
  bookFlight.Add(new SrgsSemanticInterpretationTag("$.GoingTo=$$;"));
  bookFlight.Scope = SrgsRuleScope.Public;

  // Add the rules to the SrgsDocument object and set the root rule.
  srgsDoc.Rules.Add(cities);
  srgsDoc.Rules.Add(bookFlight);
  srgsDoc.Root = bookFlight;

  // Write the completed grammar to an XML-format SRGS grammar file.
  System.Xml.XmlWriter writer =
    System.Xml.XmlWriter.Create("c:\\test\\AirportCodes.grxml");
  srgsDoc.WriteSrgs(writer);
  writer.Close();

  return srgsDoc;
}

private void CompileGrammar(SrgsDocument srgsDoc, string cfgPath)
{
  FileStream fs = new FileStream(cfgPath, FileMode.Create);
  SrgsGrammarCompiler.Compile(srgsDoc, (Stream)fs);
  fs.Close();
}

<?xml version="1.0" encoding="utf-8"?>
<grammar xml:lang="en-US" root="flightBooker" 
tag-format="semantics-ms/1.0" version="1.0" 
xmlns="http://www.w3.org/2001/06/grammar">

  <rule id="flightBooker" scope="public">
    <item> I want to fly from </item>
    <ruleref uri="#flightCities" />
    <tag> $.LeavingFrom=$$; </tag>
    <item> to </item>
    <ruleref uri="#flightCities" />
    <tag> $.GoingTo=$$; </tag>
  </rule>

  <rule id="flightCities" scope="private">
    <one-of>
      <item> Chicago <tag> $="ORD"; </tag></item>
      <item> Boston <tag> $="BOS"; </tag></item>
      <item> Miami <tag> $="MIA"; </tag></item>
      <item> Dallas <tag> $="DFW"; </tag></item>
    </one-of>
  </rule>

</grammar>

private void Form1_Load(object sender, EventArgs e)
{
  sre = new SpeechRecognitionEngine(new System.Globalization.CultureInfo("en-US"));
  string grammarPath = @"C:\test\";
  
  FileStream fs = new FileStream(grammarPath + "AirportCodes.cfg", FileMode.Create);
  SrgsGrammarCompiler.Compile(grammarPath + "AirportCodes.grxml", (Stream)fs);
  fs.Close();
  Grammar gr = new Grammar(grammarPath + "AirportCodes.cfg", "flightBooker");
  
  sre.LoadGrammar(gr);

  sre.SpeechRecognized += new EventHandler<SpeechRecognizedEventArgs>(sre_SpeechRecognized);
  sre.SetInputToDefaultAudioDevice();
  sre.RecognizeAsync(RecognizeMode.Multiple);
}

string grammarPath = @"C:\test\";
string xmlGrammar = grammarPath + "AirportCodes.grxml";
string cfgGrammar = grammarPath + "AirportCodes.cfg";
 
FileStream fs = new FileStream(cfgGrammar, FileMode.Create);
XmlReader reader = XmlReader.Create(xmlGrammar);

SrgsGrammarCompiler.Compile(reader, (Stream)fs);
fs.Close();
Grammar g = new Grammar(cfgGrammar, "flightBooker");
sre.LoadGrammar(g);