The imperfect tense verb is often used to express present time. Like any Arabic verb, the imperfect tense does not exist without a subject marker. An imperfect verb always has a subject marker prefix, but certain conjugation forms have an additional subject marker, so they have two subject markers. There are a total of 11 distinct forms of the subject marker of the imperfect verb. In the singular there are four possibilities. Only four distinct forms exist in the singular because the second person masculine and the third person feminine are identical. In the dual there are two possibilities. There are only two distinct forms. No first person form exists, and there is no distinction between masculine and feminine for the second person. Additionally, there is one form for the third person feminine and the second person masculine and feminine. In the plural there are five distinct forms of the subject marker for the imperfect verb.