` 1 ` : She hasn't come back to her hometown for 4 years
` -> ` Cấu trúc : S + have / has + VPII + for + 1 khoảng thời gian
` 2 ` : He has worked as a bank clerk for 3 months
` -> ` Cấu trúc : S + have / has + VPII + for + 1 khoảng thời gian
` 3 ` : We have flown to Singarpore for 5 years
` -> ` Cấu trúc : S + have / has + VPII + for + 1 khoảng thời gian