What are the two major kinds of word classes? Briefly explain th

What are the two major kinds of word classes? Briefly explain them.
【正确答案】：There are two major kinds of word classes in English: open class and closed class. Nouns (N), verbs (V), adjectives (Adj) and adverbs (Adv) are known as open classes because their membership is fairly open-ended, in the sense that we can readily coin new words to add to them. The closed classes, however, have a fairly fixed membership. They are determiners (Det), pronouns (Pron), prepositions (Prep), conjunctions (Conj), auxiliaries (Aux).