Verbs do not have tenses and are not conjugated. There are at least three aspects for verbs that are indicated by a modal word before the verb and any object nouns. The aspects are the completive ("daahir gasu"), the incompletive ("daahir gasu si") and the subjunctive ("afiri ŋwaaray nufa"). (Beginning grammars for foreigners sometimes inaccurately call the first two "past and present tenses".) There is also an imperative and a continuing or progressive construction. Lack of a modal marker indicates either the affirmative completive aspect (if there is a subject and no object) or the singular affirmative imperative (if there is no subject). There is a special modal marker, "ka" or "ga", according to the dialect, to indicate the completive aspect with emphasis on the subject. Different markers are used to indicate a negative sentence.