like: Where were they last week? — They were on vacation. → →
570
Where were they last week? — They were on vacation. ☊ 
Họ ở đâu tuần trước? - Họ đi nghỉ. ☊ Where were they last week? — They were on vacation. ☊ Họ ở đâu tuần trước? - Họ đi nghỉ. ☊