The purpose of this study is to demonstrate the existence of the category ‘comment clause’ whose range of use by far exceeds the traditional comment-on-topic category. In addition to a topicalized noun, the comment clause may have in its scope an element in focus, an adverbial phrase, and most important, a wide variety of clauses. The distinction between the many kinds of complex sentences and the simple sentence with a comment clause boils down to what element is in the scope of the comment clause. The data for the present study come from Wandala (Central Chadic), where the comment clause is overtly marked. The importance of this study transcends Wandala or Chadic languages, as it provides an explanation, applicable cross-linguistically, for the formal syncretism involving a variety of functions considered hitherto unrelated.