Curses, bad wishes, and maledictions - collectively referred to as imprecations, or imprecatives - often appear in an imperative form, as if telling the addressee what to do and where to go, to their detriment. Despite their imperative disguise, they stand apart from true commands in their syntactic properties. Imperative forms have a multitude of uses: they often occur in greeting and farewell formulae, expressions of thanks, and other contexts, without any overtones of a command or a request. Imperative forms in imprecatives, curses and maledictions can be looked at on a par with such speech formulae. However, the “imperative disguise” of imprecations is not universal. An imperative form may be too strong to use in an imprecation or in a curse. This is the case in Manambu, a Papuan language from East Sepik Province (PNG). Tariana, an Arawak language from the multilingual Vaupés River Basin area in northwest Amazonia (Brazil), has a special “malefactive” imperative whose main meaning is to express bad wishes. The form itself was developed as a result of extensive contact with Tucano, the major lingua franca of the area. The discussion is based on immersion fieldwork by the author - the only way of experiencing and documenting the language in its spontaneous use.