11. My father stopped smoking two years ago.
-> My father hasn't smoked for two years
12. It's ten years since they last drank this wine.
-> They haven't drunk this wine for  ten years
12. We have learnt English for four years
.-->We started to learn English four years ago
13.My father started to give up smoking last year
.-->My father has given up smoking since last year
14. They have worked in that factory since 2001.
-->They started. to work in that factory in 2001.