1 he has worked for this company for a year
-> cấu trúc worked for + N
-> thì HTHT + for dạng khẳng định ta có cấu trúc : S + have / has + VPII + for + 1 khoảng thòi gian
2 i haven't visited HN before
-> thì HTHt + before dạng phủ định
-> S + haven't / hasn't + VPII + before
3 how long have you studied this cooker
-> how long + thì HTHT dạng nghi vấn
-> cấu trúc : how long + have / has + S + VPII
4 the last time i saw him was 8 days ago
-> thì QKĐ kết hợp câu hoi the las time ở dạng khẳng định
-> the last time + S + v2 + was + 1 khoảng thời gian
