Interpersonal or evaluative meaning has been described in systemic functional linguistics with the help of appraisal theory (Martin & White 2005), which distinguishes between different types of evaluation. One sub-system of APPRAISAL is ATTITUDE, which is further divided into APPRECIATION, JUDGEMENT and AFFECT. This paper uses corpus-linguistic evidence to investigate how far linguistic patterns support this classification, and whether they can be used as a ‘diagnostic’ for distinguishing types of ATTITUDE (as has been proposed in appraisal theory). It argues that two different aspects of APPRAISAL need to be considered: the kinds of attitudinal lexis (in terms of evaluative standards which are inscribed in this lexis) and the kinds of attitudinal targets or types of attitudinal assessment, and that this distinction has not been sufficiently considered in appraisal theory so far. A preliminary classification of attitudinal lexis is also suggested, and a new sub-category of ATTITUDE proposed (COVERT AFFECT).