‘It’s not necessary to come to the train station to meet me.' You have to / don’t have to meet her at the train station.

Students mustn't run in school buildings.

‘It's not necessary to book a hotel; you can stay in our spare room.' You mu s tn’t / don’t have to stay in a hotel.

All passengers must fasten their seatbelts.

‘In my country, you can carry your passport with you if you want, but it's not necessary.' In her country, you don’t need to / mu s tn’t carry your passport with you.

‘The instructions tell you to write in pencil.' You must / n e ed n ’t write in pencil.

You don't need to buy me a birthday present.

I have to do some work on my project this evening.

‘Smoking isn't allowed in the airport.’ You mu s tn ’t / don’t have to smoke in the airport.

We have to pay the electricity bill before Friday.

It's kind of you to offer to help, but you really don't need to.

‘You can contact us by either phone or e-mail.' You mu s tn’t / don’t have to phone them.