1. When he arrived I (clean) the house already.
2. By six o´clock she (finish) her homework.
3. Sandra called me at 2, but I (leave) by then.
4. I was surprised when I met her. I (not meet) anyone like her before.
5. How was your trip to Paris? you (be) there before?
6. If I (know) the answer I would have passed the test.