28 Jan 2017 Home » Grammar » Modals of Deduction Modals of Deduction Posted in Grammar By englishlearn_admin On January 28, 2017 Modals of Deduction Certain, possibly true, not true. Must have + past part, may/might/could have + past part and etc… Follow the list; Tags:deduction, english, grammar, modals, study, vocabulary, words Related Posts Uses of Either and Neither With Examples Using Since, For, While, As, By the Time, Until, Till and As Soon As The use of certain tenses