Fill in the gaps with the correct form of the verb 'have to'. Add a pronoun if necessary. 1. Hi, Jack! Why ... go back to the office yesterday? 2. Why ... stay at work late next Friday? 3. What ... pay for? 4. It's so good that I ... work on Saturday. I'll have a chance to get some sleep! 5. I thought you ... work last week. You went skiing with us!