I've seen him wearing his coat. COMPARE THE SENTENCES MUST MUST HAVE Do you know where Tom is? Do you know where Tom is? I need to talk to him. I can't see him anywhere. must have Oh, he left. Well, it's 8 o'clock. He be at home. must I've seen him wearing his coat.

- He MUST be at home. - He MUST HAVE left. Must + base form certainty that something is true - He MUST be at home. Must have + Past participle certainty or logical conclusion about a past action - He MUST HAVE left.

COMPARE should/ought to Why didn't she invite me to the party? You read your e-mails. They could contact you should/ought to have You read sooner than you expect your e-mails. She invited everyone last week

You SHOULD/OUGHT TO read your e-mails advice/ suggestion Should/Ought to + base form Something you should do You SHOULD/OUGHT TO read your e-mails Should have/Ought to have + past participle a criticism or regret about a past event Something you should have done but you didn't You SHOULD/OUGHT TO HAVE read your e-mails

COMPARE You tell him. shouldn't You told him. shouldn't have He could get angry. He is angry now. SHOULDN'T HAVE + PAST PARTICIPLE SHOULDN'T + BASE FORM CRITICISM OR REGRET ADVICE ABOUT A PAST EVENT Something you shouldn't have done Something you shouldn't do but you did

COMPARE Why is she so late? How will she get here? I don't know, actually. She taken may/might have She take the bus. may/might the wrong bus

She MAY/MIGHT take the bus base form May/Might + a guess about the future, a possibility in the future She MAY/MIGHT take the bus May have/Might have+ past participle a guess about a past action, a possibility in the past She MAY/MIGHT HAVE taken the wrong bus

COMPARE thing to do. Be careful! It was a stupid You hurt yourself could thing to do. You hurt yourself could have

You COULD hurt yourself Could + base form Possibility that something could happen, could be done You COULD hurt yourself Could have + past participle Possibility that something could have happened, but it didn't happen Possibility that something could have been done, but it wasn't done You COULD HAVE hurt yourself

Would have + past participle I called him, but I would have didn't have my mobile Would have + past participle Something I would have liked to do but I didn't because of something not depending on my willingness