vocabulary

1.vocabulary（词汇）有时指“所识单词的总数”，有时指“所用单词的总数”。决不可用来指一个单词，如不可说He has only a few hundred vocabularies，该改作He has a vocabulary of only a few hundred words。复数形式vocabularies是“多种词汇”，如the vocabularies of geographical and occupational dialects。

2.vocabulary有时被用作物质名词。例如：The selection of vocabulary is of great importance in teaching elementary English.