In Upper Sorbian, as in the other contemporary Slavic languages, aspect is a grammatical category that characterizes the verbal system in its entirety. With the possible exception of certain types of verbs that are conventionally considered ‘biaspectual’,1 each verb form in the language expresses one of two aspects—perfective or imperfective. In most instances, verbs that share the same morphemic base and the same lexical meaning constitute a pair of aspectually complementary verbs; these are referred to as an ‘aspectual pair’. Thus, the Upper Sorbian (hereafter, USo) verb cˇinic´ is an aspectually imperfective verb signifying ‘to do’, and it is paired with the aspectually perfective verb scˇinic´ which likewise signifies ‘to do’....