1) I found a briefcase on the train. – You ought to take it to the police station as soon as possible.
2) Did you phone Alan yesterday? – No, I didn’t need to. He came round to see me.
3) Sorry, I’m late. – You should wear a watch.
4) You needn’t go to the post office. I’ll go there later.
5) Could I use your mobile phone, please? – Yes, of course.
6) Helen should be here by now. – She could have missed the train.
7) Where’s Collin? – I’m not sure. He might be in the study.
8) I ran all the way to work, but I needn’t have hurried because I was the first person to arrive.