Grammar 3 Choose the correct item. 1 You can't/might not go until the light turns green 2 You mustn't/don't have to drive me to the airport, I can take a taxi. 3 I needn't/ought not pick the tickets up because the airline has posted them to me. 4 Can/Need I come on the trip with you, please? 5 They ought/must to get vaccinated before going to Africa. 6 They can/must get the underground as it's quicker than the bus. 7 May/Need I order a taxi from here? 8 He can't/needn't come with us because he's got a doctor's appointment today.​