如何选择习语来理解我的语音识别软件c#

好了，大家好，我现在做了一个小ap语音识别，但现在他只理解西班牙语，如果我用英语说话，他把随机单词放在文本框列表上，你现在如何让他也理解英语，我怎么能让他明白我一点清楚吗?

public partial class MainWindow : Window
{
    private SpeechRecognitionEngine recognizer = new SpeechRecognitionEngine();
    public MainWindow()
    {
        InitializeComponent();
    }
    private void ButtonStart(object sender, RoutedEventArgs e)
    {
        recognizer.SetInputToDefaultAudioDevice();
        recognizer.LoadGrammar(new DictationGrammar());
        recognizer.SpeechRecognized += recognizer_SpeechRecognized;
        recognizer.RecognizeAsync(RecognizeMode.Multiple);
    }
    void recognizer_SpeechRecognized(object sender, SpeechRecognizedEventArgs e)
    {
        foreach (RecognizedWordUnit word in e.Result.Words)
        {
            listBoxResult.Items.Add(word.Text);
        }
    }
}

}