Fill in the Blanks Modals: ability or obligation3Online version practice these modal verbs by Alvar Garcia Soriano 1 Put in ? mustn't' or ? don't / doesn't have to' : We miss the train , it's the last one tonight . She do this work today , because she can do it tomorrow . I clean the floor today because I cleaned it yesterday . We forget to lock all the doors before we leave . We stay in a hotel in London , we can stay with my brother . I spend too much money today . I've only got a little left . They get up early today , because it's Sunday . I eat too much cake , or I'll get fat !