In colloquial Swedish, -is suffixation is a productive derivational process. The suffix -is has many diminutive-like properties (e.g., -is combines with truncated bases or bases of different lexical classes). As its main use is not to convey smallness but rather a subjective, qualitative evaluation, the present study addresses -is suffixation within evaluative morphology theory. Based on corpus-data from social media texts, +500 -is words (types) are analyzed for formation pattern, lexical class, and gender. The majority of -is words are uter gender nouns, mostly referring to animate referents, a few have neuter gender, mostly referring to inanimates, and some are adjectives, adverbs, or interjections. Semantically, some -is words are homonymous or polysemous. The study holds that there are different, more or less regular subpatterns of -is suffixation. It also suggests that -is suffixation might be on its way to becoming regularized towards forming nouns with uter gender and animate referents. However, as new and old words on -is exist side by side in contemporary language, -is words lie on a continuum, with regular morphological subpatterns at one end and irregular formations at the other.