The future perfect is used to report on what will have been completed by a certain point in the future. The tense is not often used in everyday speech. However, advanced level learners should be able to understand this tense at least from a passive point of view, if not be able to use the future perfect from time to time. The most important contrast you will need to draw is the difference between the two future perfect forms: the future perfect which focuses on completed actions and the future perfect continuous which focuses on the duration of an activity up to a future point in time. Here's an example to help clarify:
We'll have completed the research by next Friday.
They'll have been working for ten hours by three o'clock this afternoon.
In the first case, the action is completed. With the future perfect continuous, there is no clear indication whether the action will continue or not.
Practicing the Future Perfect
Explaining on the Board
Use a future perfect timeline to help illustrate the use of the future perfect. If the students have also studied the future perfect continuous, contrasting this timeline will help clear up any misunderstanding between the two forms. Point out that no changes in conjugation are required as will is used as the auxiliary verb. Pointing out the structure on the board will also help with understanding.
Subject + will + have + participle + objects
Tom will have visited ten major cities by the end of his tour.
The students will have learned all twelve tenses by the time we finish this class.
Importance of 'By' as a Time Expression / Time Clause
The preposition 'by' introduces the time by which an action will have been completed. Make sure to point out that the 'by' is used to either introduce a future time clause conjugated in the present simple or specific point in time.
Anna will have written two reports by the end of the term.
Jack will have performed the complete works of Chopin by the time he finishes this concert tour.
Practicing the Form
One of the best ways to practice the future perfect in the classroom is to have students think in terms of goals. I suggest starting off with the class you are teaching. Provide an overview of the goals of curriculum in your class. Write objectives on the board and then ask students what they will have learned by the end of the semester or term. For example:
Class Learning Goals
All twelve tenses
Reported Speech Conversations about Work Vocabulary Focus on Terms Related to Vacations, Sporting Equipment, Work Environment Pronunciation review of stress and intonation
Teacher: What's one thing we will have studied by the end of this semester?
Student 1: We'll have learned all twelve tenses, as well as reported speech.
Teacher: What's one more thing we will have studied by the end of this semester?
Student 2: We'll have reviewed the use of stress of intonation to help with pronunciation.
Teacher: What's something else we will have studied by the end of this semester?
Student 3: We'll have had a number of conversations about work.
Next, ask students to write down their own goals for various points in the future. This exercise can easily be combined with a job interviewing activity in which students express what they hope to be in five years' time. This time of concrete example will also help students understand the practical usage of the future perfect form.
Interviewer: Where would you like to be in five years' time?
Interviewee: I expect that I will have been promoted to department manager by 2017.
Students will likely have problems using this form due to the long string of verbs necessary, as well as the fact that the form is not commonly used in daily speech. Make sure to point out that students should strive to have a passive understanding of the verb, but not necessarily expect to actively be able to use the form. Difficulties may also arise in understanding the choice between the simple or continuous form of perfect tenses in general. his discussion of simple or continuous perfect forms can help students understand the differences between the two forms.