`color{red}{#lgdr}`

`1` After Samamtha had learned to ski , she went on the skiing holiday .

`2` Before Helen and Mark went on a honeymoon to Mauritius , they had gotten married .

`-` Cấu trúc liên hệ giữa thì quá khứ đơn và quá khứ hoàn thành .

`<=>` Before + S + V(quá khứ) + O , S + had + V3/Vpp + O .

`<=>` After + S + had + V3/Vpp + O , S + V(quá khứ) + O .