It is important to know about the frequency of a word in the language, ie knowing the degree of probability of coming across the word in speech or in print. In English, for example, written and spoken forms of language can be quite different. Some English lexical items are far more frequent in speech than in writing, such as 'indeed', 'actually' and 'well'. Other items, such as 'former', 'latter', mainly occur in the written language. Quite apart from the frequency of the word in general contexts, some items may need to be taught above more common ones, simply because of their currency in the discipline that our learners are studying.