How many English word classes are there?

How many English word classes are there? There are four major word classes: verb, noun, adjective, adverb. There are five other word classes: determiners, preposition, pronoun, conjunction, interjection. So there are nine word classes (or parts of speech) in total.

There are four major word classes: verb, noun, adjective, adverb. There are five other word classes: determiners, preposition, pronoun, conjunction, interjection. So there are nine word classes (or parts of speech) in total.