Just like other semantic subtypes of nouns such as event nouns or agent nouns, collectives may be morphologically opaque lexemes, but they are also regularly derived in many languages. Perhaps not a word-formation category as productive as event nouns or agent nouns, collective nouns still represent a category associated with particular means of word formation, in the case of the Romance languages by means of derivational suffixes. The Romance languages all have suffixes for deriving collectives, but only very few go directly back to Latin. In most cases, they evolve from other derivational suffixes via metonymic changes of individual derived nouns, notably event nouns and quality nouns. Due to the ubiquity of these changes, series of semantically and morphologically equivalent collectives trigger functional changes of the suffixes themselves, which may then acquire collective meaning. Most of these suffixes are pan-Romance, in many cases going back to very early changes, or to inter-Romance loans. The different Romance languages have overlapping inventories of suffixes, with different degrees of productivity and different semantic niches. The ease of transition from event or quality noun to collective also explains why only few suffixes are exclusively used for the derivation of collective nouns.