This document discusses different ways to express obligation, necessity, prohibition, and advice in English using modal verbs and expressions. It explains that "must" and "have to" both express obligation or necessity, with "have to" being more common for general rules and "must" for specific instances. "Don't have to" means there is no obligation, while "mustn't" expresses prohibition. "Should" and "shouldn't" are used to give advice or opinion, with "should" being less strong than "must" or "have to". The document provides examples for how to use each expression appropriately.

1. Must, haveto, shouldOBLIGATION NEFi 3A

2. Overview Obligation/necessity: haveto / must+ infinitive No obligation /necessity: don’thaveto+ infinitive Prohibition: mustn’t + infinitive Adviceoropinion: should/shouldn’t+ infinitive

3. Obligation/Necessityhavetoormust+ infinitive Must and havetohave a similar meaning Havetois more commonforgeneral, externalobligations (like rules orlaws) I havetowear a shirt and tie at work(it’s a rule) Mustis more commonforspecific (i.e.ononeoccasion) orpersonalobligations I mustbuy a new shirt – thisoneistoooldnow You can use havetoormustforstrongrecommendations Youhaveto/ mustseethat film. It’sfantastic.

4. Obligation/Necessityhavetoormust+ infinitive Havetois a normal verb and itexists in all tenses Mustis a modal verb. The onlyforms are must and mustn’t. Forallother tenses, use haveto. Havegottoisoftenusedinstead of havetoin spokenEnglish I’vegottogonow. it’svery late.

5. No obligation /necessity: don’thaveto+ infinitiveProhibition: mustn’t + infinitive Use don’thavetotosaythatyou can do something, butit’snotnecessary/you’renotobligedto do it. You can also use needn’t + infinitivewiththesamemeaning Don’thavetoand mustn’t are completelydifferent in meaning. Compare: Youmustn’t drive alongthisstreet(it’sagainstthelaw, prohibited) Youdon’thavetodrive – we can get a train(= you can drive ifyouwant, butit’snotnecessary/obligatory)

6. Prohibition: mustn’t + infinitive You can often use can’tornotallowedtoinstead of mustn’t Youmustn’tparkhere Youcan’tparkhere You’renotallowedtoparkhere

7. Adviceoropinion: should/shouldn’t+ infinitive Shouldisnot as strong as must / haveto. We use ittosayifwethinksomethingistherightorwrongthingto do. Youshouldtakewarmclothes, as itmightbecold at night. The governmentshould do somethingabouttheproblem.

8. Adviceoropinion: should/shouldn’t+ infinitive Shouldis a modal verb. The onlyforms are should and shouldn’t You can also use oughttooroughtnottowiththesamemeaning YoushouldtakewarmclotheswithyoutoDublin. YououghttotakewarmclotheswithyoutoDublin.