The past perfect continuous is very similar to the present perfect continuous.
It is constructed by using: subject + had been + present participle (-ing)
I had been walking in such a daze that I walked into a window.
He had been enjoying his ice cream cone when a bird stole it!
When I found them on the mountain, they had been walking for hours.
By the time the song ended, we had been dancing for sixty seconds.
She had been playing with yarn for so long she fell asleep!
He had been learning to play the sax for years before his first performance.
Use the past perfect continuous to talk about something that had been going on for some time before something else happened. There are usually two separate things that happen in a past perfect continuous statement.
Exercise
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