Different between has been and had been?

"Has been" is used in the present perfect tense to indicate that something started in the past and is still ongoing or has just recently ended. For example, "He has been working on the project for two weeks."

"Had been" is used in the past perfect tense to indicate that something had started and ended in the past before another action took place. For example, "She had been studying for hours before she finally took a break."

Has been is used to describe an action or state that started in the past and is still ongoing in the present. It is often used with the present perfect tense.

Example:
- She has been studying for her exam all week. (She started studying in the past and is still studying now.)

Had been is used to describe an action or state that started in the past and ended in the past. It is often used with the past perfect tense.

Example:
- She had been studying for her exam all week when she finally took it. (She started studying in the past and stopped studying before she took the exam.)

Here is a table summarizing the key differences between has been and had been:

| Tense | Meaning | Example |
|---|---|---|
| Present perfect | Action or state that started in the past and is still ongoing in the present | She has been studying for her exam all week. |
| Past perfect | Action or state that started in the past and ended in the past | She had been studying for her exam all week when she finally took it. |

It is important to note that the choice between has been and had been is often determined by the context of the sentence.