The list of groups of words included:
One particular group should always be included, that of interjections, in that new words standing in for sounds are being formed and added from many technical backgrounds, as well as from sources such as comics and subtitling. It is in these that one will encounter the noises of motor revving, sirens, mechanical sounds and violence, continuously being updated. Examples here are: vroom!, va-va-voom!, zonk!, grrh!, and so on.
Closed-class words are words belonging to a class to which no new words can be added readily such as prepositions[?], conjunctions, pronouns, etc.
wikipedia.org dumped 2003-03-17 with terodump