manner of the weak verbs.) The chief verbs of this closed class are can–could, may–might, shall–should, will–would, and must and ought (These last two have no preterites. They were originally preterites themselves). There are also dare and need, which follow the same pattern (no -s) in some contexts: "Dare he jump? She needn't worry" (dare derives from a preterite-present verb, but need is from an Old English regular verb). In some cases, used to is also listed as a modal verb. All the modal verbs both in their present and preterite forms-except for dare, need and used to-usually refer to the present or the future, not the past ("Could you do it now? Should I ask him for help?"). To express the past, modal verbs typically use suppletive forms (can – be able to, may – be allowed to, must – have to/be obliged to). The only two modal verbs that do distinguish the preterite forms are dare and need (dared (durst) and needed respectively). See . Two verbs (be and go) that contain suppletive forms, i.e. one or more of their parts came from an entirely different root. With go this applies to the past tense went, which is originally from the verb wend. With be it applies to a number of different forms (see below). For details, see Indo-European copula (for be) and the article on the verb go. Derived from be is the defective verb beware, which does not inflect in normal use and which appears only in those forms in which the plain form of be would be used, namely the infinitive, the imperative, and the subjunctive. The verb do, which has the reduplicated form did for its past tense, an irregularity that is shared with other Germanic languages. Its past participle done can be compared to typical strong participles in -[e]n; however both this and the third person present tense does feature a short vowel in modern pronunciation: , . Verbs with irregular present tenses Apart from the modal verbs, which are irregular in that they do not take an -s in the third person (see above), the only verbs with irregular present tense forms are be, do, have and say (and prefixed forms of these, such as undo and gainsay, which conjugate in the same way as the basic forms). The verb be has multiple irregular forms. In the present indicative it has am