This paper studies four grammatical markers of emotions in Tacana, an Amazonian language from the Takanan family spoken in Northern Bolivia. Two markers express positive emotions, chidi 'affection' and ichenu 'compassion'. The other two express negative emotions: base 'depreciation 1' and madha 'de-preciation 2'. The paper also provides a historical-comparative study of similar morphemes in the other Takanan languages (Araona, Cavineña, Ese Ejja and Reyesano). The Tacana affection morpheme is probably reconstructible to a diminutive marker in proto-Takanan. The compassion and two depreciation morphemes are not reconstructible but recent grammaticalizations of lexical items still used in the different Takanan languages. Interestingly, these lexemes do not display any synchronic or diachronic link with the expression of "diminutivization" or "augmentativization". Therefore, this paper suggests that the morphological expression of emotions should be studied in its own right, and not necessarily as a subtype of the evaluative field of research.