Testing the ability to write a simple sentence has long formed part of the clinical assessment of the cognitive state in the elderly, and has even been incorporated into standard brief cognitive tests (Folstein et al, 1975). Writing a sentence tests a number of faculties including language skills and praxis. As part of a comparative study of four tests of cognitive function—the Felix Post Unit (Institute of Psychiatry, 1987), Mini Mental State Examination (Folstein et al, 1975), Abbreviated Mental Test (Qureshi & Hodkinson, 1974) and Medical Research Council (MRC, 1987) – sentences written by 158 elderly newly admitted psychiatric patients, as requested in the Mini Mental State, were collected. Our aims were to assess the value of sentence-writing in discriminating between dementia and depression, and to compare the style and content of what was written. Would the material chosen by the patients for their sentences be associated with their diagnoses? In particular, would depressives write miserable sentences and the demented be more likely to write nonsense?