Questions & Discussions (about the course or NLP in general)

Open grammatical categories are usually nouns, verbs, adjectives, and adverbs. There are closed grammatical categories as well, such as pronouns, conjunctions, and determiners. There is no simpler way of creating a new pronoun, conjunction, or determiner since they are part of the syntactic knowledge of a particular language. Hence, when we encounter an OoV form, its grammatical category is likely to be one from the set of open grammatical categories.