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))Mary won't have filled out the paperwork for the student food programs by six o'clock.
(Question Word) + will + subject + have + participle form of verb?What kinds of meat will they have offered by this time next month?
The arena will have filled with people by the time the rock concert begins.
Mary won't have filled out the paperwork for the student food programs by six o'clock.
They will have eaten in all the local restaurants by the time their vacation is over.
The symphony won't have hired a staff for its in-house sales department in time for the first concert.
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