大学英语词法用法.ppt

词法 The rules and usages of words The rules of words Word classes Word formation The conversion of words Word Classes Word classes such as noun, verb, adjective, etc., are traditionally called parts of speech. There is not a fixed number of word classes. We can set up as many classes and subclasses as we need for our analysis. open classes and closed classes Word classes can be divided into open classes and closed classes. Open classes are readily open to new words; closed classes are limited classes that rarely admit new words. For example, it is easy to create new nouns, but not new pronouns. Open classes noun ：Paul, paper, speech, play Adjective： young, cheerful, dark, round main verb ：talk, become, like, play adverb ：carefully, firmly, confidentially Closed classes pronoun ：she, somebody, one, who, that Determiner： a, the, that, each, some auxiliary (verb) ：can, may, will, have, be, do conjunction ：and, that, in order that, if, though Preposition： of, at, to, in spite of There are also some more minor classes, such as the numerals (one, twenty-three, first) and the interjections (oh, ah, ouch). And there are some words that do not fit anywhere and should be treated individually, such as the negative not and the infinitive marker to (as in to say). multiple membership of word classes. some words are listed in more than one class. For instance, play is both a noun and a verb; that is a pronoun, a determiner, and a conjunction. Many more examples could be given of multiple membership of word classes. We can identify the class of some words by their form, as we will see in later sections of this chapter. But very often we can tell the class of a word only from its use in a context. I expect a reply before the end of the month. You should reply before the end of the month. suffixes We recognize the class of a word by its use in context. Some words have suffixes (endings added to words to form new words) that help to signal the class they belong to. These suffixes