The built-in dictation grammar is used for the SpeechRecognizerUI when the grammar is not added to the grammar set of the SpeechRecognizerUI object.
Below is a sample code snippet demonstrating how to set and use the Web Search Grammars for recognizing speech.
Using Web Search Grammars with SpeechRecognizerUI in Windows Phone
async private void Button_Click_1(object sender, RoutedEventArgs e)
{
SpeechRecognizerUI speech = new SpeechRecognizerUI();
speech.Recognizer.Grammars.AddGrammarFromPredefinedType("Web Serach", SpeechPredefinedGrammar.WebSearch);
SpeechRecognitionUIResult result = await speech.RecognizeWithUIAsync();
if (result.ResultStatus == SpeechRecognitionUIStatus.Succeeded)
{
MessageBox.Show(result.RecognitionResult.Text);
}
}