To add to emsr2d2's post, it would be helpful if you would have submitted complete sentences with your post but in general (I always leave room for exceptions), past perfect (had + past participle e.g. "been") is used for an action that preceded another past action, e.g. "I failed the test (most recent past event) because I had been absent (oldest past event) for three weeks". Present perfect (have + past participle e.g. "been") is used for actions begun in the past and continuing to the present, "John has been a student at the university for 2 years."