I have a classification model (BERT) that classifies sentences as either question or normal sentences. But whenever a sentence has "how" word, the model chooses "question" class. How can I solve this issue? (I have a very big dataset.)
Very likely, the majority of the sentences which contain "how" in your training data are labelled as question. It's probably a problem of representativity of the training set, because otherwise the problem wouldn't be this specific. But note that it's likely that your training data contains other issues a well, possibly there are errors in the labels.