Froggy Jumps Past Modals: Degrees of certaintyVersión en línea Students have to use one of the modals of degree of certainty to complete the sentences. por Jesús Obeso 1 John _______________ gone on holiday. I saw him this morning downtown. a must have b might have c couldn't have 2 Nobody answered the phone at the clinic. It _________ closed early. a must have b may have c could have 3 She __________ left early because her car is still here. a must have b couldn't have c might have 4 They __________ forgotten about the meeting. That's why they didn't show up. a must have b must not have c could have 5 I __________ dropped my wallet at the café. I can't find it anywhere! a couldn't have b may have c must not have 6 We use 'must have' and the past participle when... a we are almost 100% sure that it was true b we are not sure if it was true c we are almost 100% sure that it was not true 7 We use 'couldn't have' and the past participle when... a we are almost 100% sure that it was true b we are not sure if it was true c we are almost 100% sure that it was not true 8 He __________ called you. His phone has been dead all day. a might have b must not have c must have 9 You __________ seen me yesterday. I was out of town! a couldn't have b must have c may have 10 We use 'might have' + the past participle when... a we are almost 100% sure that it was true b we are not sure if it was true c we are almost 100% sure that it was not true 11 She __________ studied a lot for the test; she got a perfect score. a might have b couldn't have c must have 12 They __________ gone to the museum, but I'm not sure. a must have b might have c must not have 13 He __________ known about the surprise party because he looked completely shocked. a must not have b may have c could have 14 You __________ heard the news by now — it's all over the internet! a must have b might have c must not have 15 I __________ missed your call while I was in the shower a might have b must not have c couldn't have