1.现在完成进行时(The Present Perfect Continuous Tense)表示由过去某时持续到现在的动作，由“have(has)been+现在分词”构成：
It has been raining for three hours.
She has been working the whole morning.
That's the letter I have been expecting.
What have you been arguing about?
What's the matter with you? I've been here waiting for you for 3 hours!
2.过去完成进行时(The Past Perfect Continuous Tense)：表示过去某时前一直在进行的动作，由“had been+现在分词”构成：
I asked him what he had been doing.
He had been working all day and was very tired.
She showed me the book she had been reading.
He told her that he had been thinking of her all the time.
Jane had been doing the work for a year before I took over the job.
3.将来进行时(The Future Continuous Tense)：表示将来某时正在进行的动作，或根据安排将要发生的事，由“will(shall)be+现在分词”构成：
Be sure to come at 8 o'clock. I'll be expecting you.
I'll be waiting for you outside.
Tomorrow morning I'll be seeing a friend off at the airport.
The machine will still be working tomorrow at 9 pm.