When do we use have plus past progressive form of the verb like heard?

You're likely asking about the construction "had been + verb-ing" (e.g., "had been hearing"). This is the past perfect continuous tense, and it's used to describe an action that:

* Started in the past and continued up to another point in the past.

* Was in progress before another past action or event.

Here are some examples:

* "I had been hearing strange noises all night before the power went out." (The hearing started before the power went out and continued up to that point.)

* "They had been working on the project for months before they finally finished it." (The work started in the past and continued up to the moment of finishing.)

Here are some key points to remember:

* The past perfect continuous is used to emphasize the duration of an action.

* It's often used in conjunction with a past simple verb to show the sequence of events.

* It's similar to the past perfect tense (had + past participle), but it emphasizes that the action was ongoing.

For example:

* "I had heard the news." (This just states that you heard the news at some point in the past.)

* "I had been hearing the news all day." (This emphasizes that you were continuously hearing the news for a period of time in the past.)

Let me know if you have any further questions!