S + had + V3/ed
The earlier of two past actions; cause in the past.
Use with before/after/by the time; narrative sequencing.
She had left before I arrived.
Cô ấy đã rời đi trước khi tôi đến.
They had finished dinner by the time we came.
Họ đã ăn xong trước khi chúng tôi đến.
