1.Tom began playing the piano 4 years ago.
=> Tom has been playing the piano for 4 years.
2. I started cooking for the party 4 hours ago.
=> I have been cooking for the party for 4 hours.
3. She started working as a secretary 2 years ago.
=> She has been working as a secretary for 2 years.
4. My father is reading a newspaper. He started 2 hours ago.
=> My father has been reading a newspaper for 2 hours.
5.My sister began to study English a year ago.
=> My sister has been studying English for 1 year.
6.Scientists began to fight against AIDS in 1980.
=> Scientists have been fighting against AIDS since 1980.
7.The Browns have been living in London for 20 years.
=> The Browns began to living in London 20 years ago.
8. John has worked for this electronics firm since 1999.
=> John started working for this electronics firm in 1999.
9. Women have been fighting for their rights since the middle of the 20thcentury.
=> Women began to fight for their rights in the middle of the 20th century.
10. Jack and Jill have learned to drive for 2 weeks.
=> Jack and Jill started learning to drive 2 weeks ago.
11. How long have you studied English?
=> When did you started studying English?
12. When did you begin to do research on lung cancer?
=> How long have you begun to do research on lung cancer?

1.
=> Tom has been playing the piano for 4 years.
2. 
=> I have been cooking for the party for 4 hours.
3. 
=> She has been working as a secretary for 2 years.
4. 
=> My father has been reading a newspaper for 2 hours.
5.
=> My sister has been studying English for 1 year.
6
=> Scientists have been fighting against AIDS since 1980.
7.
=> The Browns began to living in London 20 years ago.
8.
=> John started working for this electronics firm in 1999.
9.
=> Women began to fight for their rights in the middle of the 20th century.
10. 
=> Jack and Jill started learning to drive 2 weeks ago.
11. 
=> When did you started studying English?
12. 
=> How long have you begun to do research on lung cancer?