Question

what is the rule of past prefect continuous tense​

Answer 1

Answer:

The past perfect continuous tense (also known as the past perfect progressive tense) shows that an action that started in the past continued up until another time in the past. The past perfect continuous tense is constructed using had been + the verb's present participle (root + -ing).

Explanation:

Answer 2

Structure => Sub+had+been+v1+obj+since/for