1. A method to determine a part-of-speech (POS) category associated with a word in a text, the method comprising: determining a first set of candidate POS categories associated with the word based on a dictionary; determining one or more contexts in which the word is used in the text based on a first set of rules; determining a second set of candidate POS categories from the first set of candidate POS categories based on the one or more contexts; and determining the POS category from the second set of candidate POS categories based on a second set of rules.