This paper examines a series of consonantal alternations conveying ‘affective’ meanings in the South American language Mapudungun (Catrileo 1986, 2010, 2022). The processes target the rich four-place coronal inventory of the language by shifting consonants in root morphemes to palatal or dental articulations. The palatalisations are crosslinguistically common in implying small size, tenderness, closeness and politeness (e.g.[naʐki] ‘cat'→[ɲaʃki] ‘kitty’), however, the effects of dentalisation are more unexpected, implying distance, abruptness, sarcasm and rudeness (e.g.[naʐki] ‘cat'→[naθki] ‘damned cat’). While speakers evidently seem to assign sound symbolic value to the alternations, the patterns do not align neatly with cross-linguistically expected ‘synaesthetic’ correspondences, particularly to do with size symbolism and acoustic frequency (Ohala 1984, 1994). Based on historical metalinguistic commentary and corpus data, I argue that the Mapudungun alternations are long-established in the language, showing a variety of lexicalised forms, and being deeply grammatically entrenched both in their semantico-pragmatic implications and their morpho-phonological structure. As such, any sound symbolic patterns are fundamentally subordinate to the grammatical architecture. I propose that a more parsimonious analysis of the patterns is one based on floating diminutive and augmentative morphemes spreading the [distributed] and [anterior] feature nodes to the target coronal consonants, along with their language-specific pragmatics.