He has been working in this factory for 15 years
⇒ He started working in this factory 15 years ago.
Cấu trúc:
S+ started/ began +V-ing/ to V + in / at …….. / ………. ago
=S+ have/ has + P2 + since (in/at…) / for (…… ago)
(Bắt đầu làm việc gì = Làm việc gì được bao lâu)