Write a dialogue between two people. One is trying to tell the other something important while a third character (off screen maybe or outside) interrupts them up to four times with the sentence: Hurry up! We are going to be late!

Make sure that it is important that they are on time. If it is just a student house party they are going to, it may not be urgent enough. The scene ends without the important thing being said. Of course you can replace the sentence with a different one or build up the pressure by this person counting down and saying ‘Five more minutes guys, hurry up!’ followed by ‘Only three more minutes, what the hell is taking you so long?