C3: Verbs: Perfect Progressive Tense: Use the auxiliary verbs “to have” and “to be” + present participle to form the perfect progressive tense correctly: See Writing for Success Section 5.5 pp. 200-203 or the following: http://www.cws.illinois.edu/workshop/writers/perfectforms/
Perfect Progressive tense shows action in progress up until a completed time in the past, present, or future.
Past Perfect Progressive:
The pelicans had been flying back and forth all morning.
I had been sitting at my desk all weekend long.
Present Perfect Progressive:
Juanita has been dating her boyfriend since high school.
We have been getting our pictures printed at Walgreens.
Future Perfect Progressive:
Martha’s Restaurant will have been serving customers for fifty years next June.
They will have been going to the same school all the way until they graduate.