Monday, January 8, 2018

Open and closed word classes

Words may be divided into the following major word classes:

  Word class Examples

        Word class             Examples
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         Nouns                    brother, child, China, ecolgy, James,                                                                                         tree

         Main verbs            break, consider, destroy, eat, sing, talk
       
        Adjectives              angry, cold, foolish, happy, tidy,                                                                                                young
        
         Adverbs                 carefully, gradually, happily, slowly

         Pronouns                I, me, my, you, he, his, her, we, our

         Auxiliary verbs      can, could, do, may, might, will,                                                                                              would
       
         Prepositions           after, at, for, in, of, over, with, without

         Conjunctions           although, and, because, but, or, when

         Articles                   a, an, theـ
        
         Numerals                one, two, twenty, first, second, third

Some word classes are open, that is, they admit new words as members as the need arises. The major open classes are the first two above – nouns and main verbs. The class of nouns is potentially infinite, since it is continually being expanded as new discoveries are made, new products are developed and new ideas are explored. In recent years, for example, developments
in computer technology have given rise to many new nouns,
including:

       bitmap                   modem

      CD-ROM               multimedia

      dotcom                    newsgroup
   
      e-commerce            pixel
     
      e-mail                     voicemail

      Internet                   website

      laptop

These developments have also given rise to some new verbs:

      download               right-click

      upload                   double-click

      reboot

The adjective and adverb classes also admit new members from time to time, though far less prolifically than the class of nouns. The class of numerals is open, since we can always add 1 to a number to make a new number.

In contrast with this, prepositions, for instance, belong to a closed word class. We never invent new prepositions (words like after, at, before, in,with) simply because we never need them.