Write an article based on this "Start with present subjunctive. Combine the correct conjugated form of haber with “sido” for perfect subjunctive tenses."
If you want to describe a current state of being that is in doubt or is hoped for, you would use the present subjunctive. This tense is used far more often in Spanish than it is in English. While a literal translation is "to be," in this tense and mood it means more like "may be." For example, you might say, "Dudo que ella sea rica" to mean "I doubt that she is rich."   Yo sea: I am/may be.  Tú seas: You are/may be.  Él/ella/usted sea: He/she/you are/may be.  Nosotros/-as seamos: We are/may be.  Vosotros/-as seáis: You all are/may be.  Ellos/ellas/ustedes sean: They/you all are/may be. Just as with the perfect tenses in the indicative mood, you form past, present, and future subjunctive tenses with the helping verb haber. To form present perfect subjunctive (in Spanish know as pretérito pluscuamperfecto/antepretérito), use the present subjunctive of haber along with sido. Use this tense to describe a state of being in the past that is connected to one in the present, or will have happened at some point in the future. For example, you might say, "Dudo que hubiera sido rica" to mean "I doubt that she has been rich." The past perfect subjunctive is used for hypothetical or conditional states of being in the past. Use the imperfect subjunctive (in Spanish know as pretérito perfecto compuesto/antepresente) conjugation form for haber along with sido. For example, you might say, "Haya sido rico," or "I have been rich."  The future perfect subjunctive (in Spanish know as futuro compuesto/antefuturo) form of ser is used to talk about a state of being that will have been in existence in the future, or might have or could have existed in the future. Combine the simple future conjugation form of haber with the past participle sido. For example, you might say, "Yo habré sido rico," to mean "I will have been rich."