请教一个中文词性标注的问题，请大牛指点

报错：没有为类型 WordAlert 定义方法 isEnglish(String)

源码如下：
public static List recognition(List words, int offe) {
List terms = new ArrayList(words.size());
int tempOffe = 0;
String[] params = null;
for (String word : words) {

            // 获得词性 ， 先从系统辞典，再从用户自定义辞典

            AnsjItem ansjItem = DATDictionary.getItem(word);
            TermNatures tn = null;
            if ((params = UserDefineLibrary.getParams(word)) != null) {
                tn = new TermNatures(new TermNature(params[0], 1));
            } else if (ansjItem.termNatures != TermNatures.NULL) {
                tn = ansjItem.termNatures;
            } else if(WordAlert.isEnglish(word)){
                tn = TermNatures.EN ;
            } else if(WordAlert.isNumber(word)){
                tn = TermNatures.M ;
            } else{
                tn = TermNatures.NULL ;
            }
            terms.add(new Term(word, offe + tempOffe, tn));
            tempOffe += word.length();
        }
        new NatureRecognition(terms).recognition();
        return terms;
    }