superchemist-At once = immediately: ngay lập tức
Ex: Having heard the bad news, she burst into tears at once
-Once (+ thời gian): (adv) một lần ( trạng từ chỉ tần suất)
Ex: I play volleyball once a week Once (adv): đã từng ( quá khứ) (at some time in the past)
Ex: I once met you. -For once: thỉnh thoảng
Ex: She just comes here for once. -One-time( adj): trước kia (=former)/ không lặp lại
Ex: This is my one-time house.
Here is a one-time sale for all items.