To go ing form: going
Sujeito + to be (past perfect) + going
He, she, it had been going.
Sujeito + to be (past perfect) not + going
I, you, we, they had not been going.
He, she, it had not been going.
To be (past perfect) + sujeito +going
Had I, you, we, they been going?
Had he, she, it been going?
a) Descreve uma ação que começa antes de algum momento no passado e continua até aquele momento ou se interrompe um pouco antes.
I got to school at 8:30.
The teacher started explaining the lesson at 8 o’clock.
When I got to school, the teacher had been explaining the lesson for half an hour.
Quando cheguei à escola, a professora estaba explicando a lição há meia hora.