The future perfect expresses what will have occurred up to a specific point of time in the future.
Subject + will + have + participle form of verb + (object(s))They will have finished the report by the time he factors the hourly pay for his employees.
Subject + will + not + have + participle form of verb + (object(s))The symphony won't have hired a staff for its in-house sales department in time for the first concert.
(Question Word) + will + subject + have + participle form of verb?What kinds of meat will they have offered by this time next month?
What kinds of meat will they have offered by this time next month?
The staff will have alerted all the customers by the time the fire department arrives.
Mary won't have filled out the paperwork for the student food programs by six o'clock.
How will guests needs have changed by 2012?
Examples of What Will Have Happened
Time expressions: 'By' and 'By the ..'
It is important to express the point in time in the future by when something will have happened with the future perfect. Here are the two most common time expressions used with the future perfect form:
By + date or time
… by 2003.
…by the end of next week.
By the time + clause
…by the time we finish this class
…by the time you receive this letter