Lexis refers to the vocabulary or the entire stock of words in a language. The English language examination seeks to test the scope of the candidate’s vocabulary and his skills to use appropriate words in a given context. It covers such aspects as the use of items in various areas of human endeavour.
In the study of English grammatical structure, we learn how words combine with other words of form larger units. A list of words, expressions or terms that are regularly used in relation to a particular subject-matter or associated with a particular area of human activity and development is referred to as a register.