In this discussion note, I argue that we need to distinguish carefully between descriptive categories, that is, categories of particular languages, and comparative concepts, which are used for crosslinguistic comparison and are specifically created by typologists for the purposes of comparison. Descriptive formal categories cannot be equated across languages because the criteria for category assignment are different from language to language. This old structuralist insight (called categorial particularism) has recently been emphasized again by several linguists, but the idea that linguists need to identify ‘crosslinguistic categories’ before they can compare languages is still widespread, especially (but not only) in generative linguistics. Instead, what we have to do (and normally do in practice) is to create comparative concepts that allow us to identify comparable phenomena across languages and to formulate crosslinguistic generalizations. Comparative concepts have to be universally applicable, so they can only be based on other universally applicable concepts: conceptual-semantic concepts, general formal concepts, and other comparative concepts. Comparative concepts are not always purely semantically based concepts, but outside of phonology they usually contain a semantic component. The fact that typologists compare languages in terms of a separate set of concepts that is not taxonomically superordinate to descriptive linguistic categories means that typology and language-particular analysis are more independent of each other than is often thought.