$\text{1}$ They have built this house for two months . 

$\text{2}$ My father has worked in this factory since last week . 

$\text{3}$ He has lived in Ho Chi Minh city since he was 8 .

$\text{4}$ He has learnt English since he was 18 . 

$\text{5}$ They began to work in that factory five years ago . 

$\text{6}$ We started learning English four years ago . 

$\text{7}$ My father has gave up smoking since last year . 

$\text{8}$ They started to work in that factory in 2001 . 

→ S + started/began + to V/V-ing + when/in/on/time + ago/... 

→ S + has/have + Vpp + for/since + time(trong quá khứ)