Spanish Future Subjunctive
The simple future subjunctive is a tense that is rarely used nowadays. You won't find this tense in everyday conversation or even in a formal conversation. It is considered extremely old and you may see it in some sayings, some literary contexts or legal documents.
For example, there is this saying:
Donde fueres, haz lo que vieres.
When in Rome, do as the Romans do.
This tense conjugation is rarely taught when you learn Spanish as a foreign language as it is so rare nowadays. You can use the present subjunctive (El Presente de Subjuntivo) instead without changing the meaning.
You conjugate in the simple future subjunctive by adding these endings to the stem of the verb, this being the same stem as for the imperfect subjunctive (El Pretérito Imperfecto Subjuntivo):
estuviere, quisiere, pusiere, trabajares, caminares, dijéremos, habláremos, comiereis, vieren...
