Print and cut out the words individually.  Students must be in groups and it is a race to put the sentence into the correct order.  Each sentence is differentiated for mixed ability groups - simple sentence for low ability, wenn clause for higher ability students and question for middle ability.  Students really enjoy it - they have to ask you to check it and if they are incorrect, then you keep going until each sentence has been completed.  This can lead to a whole-class discussion the word order of modal verbs, and also, other possibilities for word order.