... office tomorow morning I didn't to lock the door ( Tôi không nhớ phải khoá cửa ) 3.2 Remember doing sth: Nhớ làm gì/ Nhớ điều làm ( Bây nhớ lại ) Eg:: I remember locking the door before leaving, but ... I regret to tell/ inform/ you that say that We regret to inform the passengers that the flight for Washington DC was canceled because of the bad weather We regret to inform you that your application ... doing sth/ Not doing sth: Hối tiếc ( ) làm/ Không làm điều ) Eg: He regrets leaving school early It's a big mistake I regret not following my father's advice She regretted not working hard before...