Grammar III: ModalsWhat are modal verbs?A verb is the part of speech that expresses action, condition, or being. Verbs change form toindicate person, number, tense, voice, and mood. The main verb of a sentence is often preceded byone or more auxiliary or helping verbs, which together form a complete verb. Auxiliary verbsinclude forms of “have” (has, have, had), “do” (does, do, did), and “be” (be, am, is, are, was,were, being, been) as well as the nine modal auxiliary verbscan,could,will,would,shall,should,may,might, andmust. Note thatought tois often added to the list of modal auxiliaryverbs.Modals (also calledmodal verbs, modal auxiliary verbs,modal auxiliaries) are special verbswhich behave irregularly in English. They behave a little bit differently than most English verbs.Here are some characteristics of modal verbs:They never change their form. You can't add "s", "ed", "ing" on themThey are always followed by an infinitive without "to" (i.e. the bare infinitive.)There is no “do / does” in the questionThere is no “don’t / doesn’t” in the negativeIn addition, the verbs or expressionsdare,ought to,had better,andneed notbehave like modalauxiliaries to a large extent and may be added to the above list. Moreover,Canis substituted withbe able to, and Mustis substituted withhave to.E.g. Theycanplay the piano. They willbe able toplay the piano in the futureYoumustcome early.Youhad tocome early yesterdayHere are the list of modals and functions with examples:Modal VerbExpressingExampleMust/have toStrong obligation/ compulsionYou must stop when the traffic lights turnred.logical conclusion / necessityHe must be very tired. He's been working allday long.must notProhibitionYou must not smoke in the hospital.canAbilityI can swim.PermissionCan I use your phone please?PossibilitySmoking can cause cancer.couldability in the pastWhen I was younger I could run fast.polite permissionExcuse me, could I just say something?PossibilityIt could rain tomorrow!mayPermissionMay I use your phone please?possibility, probabilityIt may rain tomorrow!
