1. Nam started studying English 5 years ago
→ Nam has been learning English for 5 years so far
2. We started to play soccer an hour ago
→ We have been playing football for an hour now 
3. She started reading this novel a week ago
→ She has been reading this book for a week  
4. He started writing this book last year
→ He has been writing this book since last year 
5. My sister began playing badminton in 1986
→ My sister has been playing badminton since 19866.
 

1. Nam has been studying English for 5 years.
2. We have been playing soccer for an hour.
3. She has been reading this novel since a week ago.
4. He has been writing this book since last year.
5. My sister has been playing badminton since 1986.