What are the two major kinds of word classes in English? What word do they consist of respectively?

What are the two major kinds of word classes in English? What word do they consist of respectively?

There are two major kinds of classes in English: open-class words and closed class words. Open-class words are nouns, verbs, adjectives and adverbs because their membership is fairly open-ended. THe closed classes have a fairly fixed membership. They are determiners, pronouns, prepositions, conjuctions and auxiliaries.