https://www.spokenenglisheasynow.com/2021/03/Past-Perfect-Continuous-in-Spoken-English.html
Spoken English Easy Now: Past Perfect Continuous in Spoken English
Past Perfect Continuous in Spoken English, Past Perfect Continuous Tense
past perfect continuousspoken englisheasy
https://engelsklaslokaal.nl/en/english-grammar-exercises/one-english-verb-form/past-perfect-continuous-exercises/
Past Perfect Continuous | Exercises | Form | The English Classroom
Dec 16, 2021 - Past Perfect Continuous - Exercises and Form (He had been going). Practise using the Past Perfect Continuous in English. Practise your grammar.
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https://igorposner.net/Past-Perfect-Continuous
Past Perfect Continuous — Igor Posner
2006-2010 Past Perfect Continuous In 2006, Igor Posner returned to St. Petersburg, the city where he was born, for the first time in 14 years. Confronted by...
past perfect continuousigorposner