verb "to be" with the perfect active participle, for example "I shall have loosed". In the middle and passive voice, the periphrastic construction is also very common, but a synthetic construction is found as well, by adding the endings of the future tense to the perfect stem, for example "I shall have been loosed". The synthetic construction is rare, and found only with a few verbs. Latin In Latin conjugation, the active future perfect is formed by suffixing the future forms of esse "to be" to the perfect stem of the verb. An exception is the active indicative third person plural, where the suffix is -erint instead of the expected -erunt. E.g. amaverint, not **amaverunt. The passive future perfect is formed using the passive perfect participle and the future of esse. Note that the participle is inflected like a normal adjective, i.e. it agrees grammatically with the subject. Italian The future perfect is used to say that something will happen in the future but before the time of the main sentence. It is called futuro anteriore and is formed by using the appropriate auxiliary verb "to be" (essere) or "to have" (avere) in the future simple tense followed by the past participle: Io avrò mangiato ("I will have eaten") Io sarò andato/a ("I will have gone") It is also used for to express doubt about the past like the English use of "must have": Carlo e sua moglie non si parlano più: avranno litigato ("Carlo and his wife are no longer talking: they must have quarrelled") To translate "By the time/When I have done this, you will have done that", Italian uses the double future: Quando io avrò fatto questo, tu avrai fatto quello. Romanian The Romanian viitor anterior is used to refer to an action that will happen (and finish) before another future action. It is formed by the future simple tense of a fi (to be) followed by the participle of the verb. Eu voi fi ajuns acasă deja la ora 11. ("I will have arrived home already at 11 o'clock.") Serbian It is usually restricted to conditional clauses. It is formed from a conjugated form of auxiliary verb biti ("to be") in the imperfective aspect plus past participle, which can be in any aspect and is conjugated for gender and number. Since Serbo-Croatian has a developed aspect system this tense is considered redundant. Kad budem pojeo... ("When