9. A system comprising: at least one processor; and memory storing computer-executable instructions that, when executed by the at least one processor, cause the system to: train a classifier using a confirmed annotation, the training comprising updating a corpus of the classifier with a feature extracted from the confirmed annotation, the feature comprising a hypernym of the confirmed annotation and at least one word of the confirmed annotation, the at least one word being adjacent to the hypernym in the confirmed annotation, and wherein extracting the feature comprises: obtaining a concatenated hypernym by concatenating at least two hypernym of the confirmed annotation, obtaining a sequence comprising the concatenated hypernym, and extracting the hypernym from a substring of the confirmed annotation corresponding to the sequence, automatically annotate a text sample and obtain an annotation candidate of a set of annotation candidates for the text sample by replacing an n-gram of the text sample with a hypernym corresponding to the n-grams, classify the set of annotation candidates for the text sample using the classifier, and derive an annotation-derived grammar rule based on an annotation candidate selected as an annotation for the text sample, derive a classifier-derived grammar rule based on the corpus of the classifier, and configure a grammar to include the annotation-derived grammar rule and the classifier-derived grammar rule.
13. The system of claim 9 wherein: the classifier is a naive Bayes (NB) classifier.