Thì quá khứ hoàn thành tiếp diễn được dùng để diễn tả quá trình xảy  ra 1 hành động bắt đầu trước một hành động khác trong quá khứ.

Cách dùng

Hành động diễn ra trước 1 hành động khác

I had been working for three hours when you arrived.
Susan had been thinking about the idea for a while when he made the suggestion.

Hành động đang xảy ra trong 1 khoảng thời gian trong quá khứ thì có 1 hành động khác xảy ra

I had been playing tennis for two hours when I sprained my ankle.
Jane had been studying for two years when he was drafted into the army.

Hành động xảy ra để chuẩn bị cho 1 hành động khác

I had been practicing for three days and was ready for the concert.
Tom had been studying hard and felt good about the test he was about to take.

Trong câu điều kiện loại 3

If I had been working on that project, we would have been successful.
She would have been ready for the test if she had been preparing diligently.

Các từ, cụm từ đi kèm:

before, when

Cấu trúc

Khẳng định

Chủ ngữ + had + been + verb + ing

I, You, He, She, We, They had been working for two hours when she telephoned.

Phủ định

Chủ ngữ + had + not (hadn’t) + been + verb + ing

I, You, He, She, We, They hadn’t been paying attention for long when he asked the question.

Nghi vấn

Từ để hỏi (thường là ‘How long’) + had + been + chủ ngữ + verb + ing ?

How long -> had he, she, you, we, they been working before he arrived?