2.5 Present Perfect or Past Perfect. 1. My sister is so upset: she (to lose) the key to the front door. 2. By the 1st of September all the children (to return) from the country. 3. Columbus (not to know) that he (to discover) America. 4. He (to discuss) this problem with a lot of people before he (to take decision). 5. I never (to be) to Greece. 6. She is very happy: her son (to finish) school.
1 has lost
2 had returned
3 . Columbus didn't know that he discovered America
4 discussed,had taken decision
5 I have never been to Greece
6 has finished