For the expression of mood, English uses a number of modal auxiliaries, such as can, may, will, shall and the past tense forms could, might, would,should. There is also a subjunctive and an imperative mood, both based on the plain form of the verb (i.e. without the third person singular -s), and which is used in subordinate clauses (e.g. subjunctive: It is important that he run every day; imperative Run!).