In Quelo's user interface (UI), a query is represented as a sequence of snippets of natural language text composing an English sentence, like the one shown below.

Some of the snippets, corresponding to classes and properties from the ontology, are active and allow to operate on the query. In order to distinguish them, active snippets are enclosed in boxes with rounded corners, having a light-blue background if the snippet corresponds to a class and a transparent one if it corresponds to a property.