Transcript of modal verbs
MODAL VERBS Introduction: Modal verbs are a type of auxiliary verbs. There are five main modal verbs: Phrases with modal verbs: Affirmative/Negative: Subject+MV+Verb Questions: Yes/No questions: MV+subject+Verb Wh- questions: Wh- word+MV+Subject+Verb Differences between normal verbs and MV: They don't take the -s in the third person They use "not" to make them negative in present simple and past simple, instead of don't or didn't They can't be used in future and past tenses Can/Could: They are used to express ability. In the present affirmative we use can. F. ex: I can speak french. In the past affirmative we use could. F. ex: I could swim when I was five. Can Could Have to Must Should Have to: It's used to express obligation or prohibition (in negative). In the present negative we use can't. F. ex: I can't drive a car. And, in the past negative, we use couldn't. F. ex: I couldn't walk when I was one. In the present affirmative, we use have to. F. ex: I have to go to school. In the past affirmative, we use had to. F. ex: Last week had to make a composition for homework. In the present negative we use mustn't. F. ex: He mustn't go out. In the past negative we also use mustn't. F. ex: He mustn't go out, but he did it. Differences between don't have to and mustn't: Don't have to means that you can if you want to. Mustn't means that something it's forbidden, you can't do it. Must: It's used to express prohibition or obligation. In present affirmative we use must. F. ex: I must study. In past affirmative we use should. F. ex: You should have taken some time off last week to get some rest. In present and past negative we use mustn't. F. ex: You mustn't swim in the river. // They mustn't play in the street, but they did it. Should: It's used to express advices, and also obligation. In present and past affirmative we use should.Full transcript
F. ex: I should be at school at 9 o'clock. // You should have run every day, because now you're fat. In present and past negative we use shouldn't.
F. ex: You shouldn't smoke. // You shouldn't have played, because you haven't pass the exams. Note: when should means obligation, the only form that can be used is present affirmative. The others are used when it means advice.