1. It often tales me thirty minutes to walk to school.
-> i often spend thirty minutes walking to school.
2. After 4 years aboard, mr.Brown
-> After Mr.Brown had been abroad for 4 years, he returned home as am excellent engineer.
3.Sarah hasn't seen her triêng since she left for the united states.
-> Sarah last saw her friend ehrn she left for united states
4. We haven't gone to a concert for ages.
-> It's ages since the last time we went to a concert for ages.