Matching Pairs have to, must & should, plusOnline version Checking vocabulary learnt/verb use MBO outdoor year1. Match the sentences or the missing word by the dots ....... by Tina Oomes-Swift 1 It isn't necessary, but it is a good idea. 2 You need to do this. It is compulsory. 3 Frustrated means... 4 Do not do this. It is prohibited (not allowed). 5 A branch might fall out of that tree, You .......................... park your car here. 6 Pessimistic means... 7 Optimistic means... 8 It is not allowed. You ..............................park your car here. 9 It is a bad idea to do this. shouldn't ...feeling annoyed that you can't do something or that something is not as you think it should be. ...positive state of mind and thinking that things will go well. mustn't You must do it. ...negative state of mind and thinking that things will go badly. You shouldn't do this. (You should not do this.) You should do it. You must not do it.