Spanish Future Perfect
El Futuro Perfecto also known as El Antefuturo
El Futuro Perfecto is the future perfect tense of the indicative mood. It's used to express actions that will happen before other actions in the future: it could be called 'the past of the future'. And sometimes it is also used to talk about what we think happened in the past.
In English, the future perfect is formed with "will have" + the past participle of the verb.
In Spanish, El Futuro Perfecto is formed with:
haber in El Futuro Imperfecto + past participle
For example
Tú habrás terminado tus deberes pronto. - You will have finished your homework soon.
No sé dónde habrá aprendido esa palabra. - I don't know where he might have learned that word.
See also: Spanish Future Tenses and All Spanish Tenses