Past perfect continuous tense

Affirmative

Rule: Subject + had+been+V1ing+ object+for/since+time.

Examples: we had been reading books since morning.
She had been reading books for two days.

  Negative

Rule: Subject+had+not+been+V1ing+ object+for/since+time.

Examples: she had not been reading books for two hours.
They had not been reading books for many years.
Singular = had not
Plural = had not

Interrogative

Rule: Had+ subject+ been+v1ing+ object+for/since+time?

Examples: Had you been liking me since 2015?
Had she been liking me for many months?

Wh Family

Rule: wh+had+subject+v3+object+for/since+time?

Examples: why had you been liking him for three years?
When had she been playing cricket since morning?