This paper explores keywords, key part-of-speech categories and key semantic categories and their role in text analysis. The first part of the paper addresses a set of issues relating to the definition of keywords and their history, the settings used in deriving keywords, the choice of reference corpora, the different kinds of keyword that emerge in one's results and the dispersion of keywords in one's data. It argues, amongst other things, that keywords are the same as style markers, and that three types of keyword can be identified: interpersonal, textual and ideational. The second part of the paper addresses the question of what precisely is to be gained from analysing key part-of-speech or key semantic domains in addition to keywords. It shows that whilst in general they add little to a keyword analysis, which is in any case methodologically more robust, there are some significant specific benefits. Answers to many of the questions posed in this paper are illustrated by a study of character-talk from Shakespeare's play Romeo and Juliet, and in this way this paper also makes a contribution to the fledging field of corpus stylistics.