ABSTRACT
The division of the meanings of words into smaller units of meaning is one of the most successful areas of modern semantics, and turns out to be useful for language learning, for most of the elementary units of meaning of one language are found in other languages. People can call these elementary units of meaning 'semantic atoms', for like atoms in chemistry that combine together into molecules, they combine together into tight clusters that can be called 'concepts' or word meanings. It is a common belief that orthographic words or syntactic formatives are the carriers of meaning. Though such words usually do have some meaning, in isolation that meaning is too often not the meaning that is expressed when they are combined with other words. This chapter discusses two separate vocabularies: the core vocabulary that contains the words used every day; and the peripheral vocabulary, the innumerable words that one uses only infrequently.
