HomeGrammarModals of ObligationModals of Obligation admin 5 August 2015 Grammar No Comments Modals of Obligation;Must; official, written rules, strong recommendationHave to; when it’s necessary to do sth(no choice), very strong recommendationShould; soft recommendation or personal advice Tweet Pin It Related Posts Common English Mistakes Present Perfect Tense vs Past Simple Tense Uses of Also, Too and SoAbout The Author admin