'had been' is a verb phrase made up of two auxiliary verbs
'had' and 'been'. It is used to indicate past perfect and past perfect continous tense, often to describe the unfolding of a past action or events that has been in progress up until a point in the past. This tense is formed by using the helping verb 'had' plus the past participle of the verb 'been'.
the verb, 'had been', is used to talk about an action that had started in the past and was ongoing until another event happened. It is the past perfect progressive form of a verb, which usually appears with 'for' or 'since' in a sentence, indicating the length of the action. It does not indicate whether the action is complete, only that it has been in progress.
1. She had been studying for the test for four hours, until she finally gave up.
2. The artist had been working on the painting since early morning.
3. I had been a guitarist before I moved to the USA.
it is important to note that when using 'had been' in a sentence, you don't need to specify the duration of the action. You also don't need to provide a final outcome of the action or the result. Additionally, be careful not to mistake 'been' with 'being' as they cannot be used interchangeably.