This is probably the most difficult tense to teach in English. Similar to the present perfect, the future perfect talks about something already having occured by a particular time in the future.
Even for natives, this is tricky to understand. Thus getting it across to your students will likely be tricky, too.
Some of these activities from busyteacher are very well thought through though. Check out more of their site for handouts and the like.
Its form is:
S (I/You/They etc.) + will + have + past participle (+verb-ing)
(+verb-ing is sometimes used - see point 3)
Here are some of the ways we use the future perfect:
1). To talk about something that would have been completed by a certain time in the future:
I will have been shopping by this time tomorrow afternoon; They’ll have finished cooking dinner by then, so make sure you’re home; Rob said we’ll have finished the carpet next week so make sure you’re ready to leave
2). 'Shall' can also be used after I and we (instead of will):
I shall have been shopping….; Rob said we shall have finished….
3). A continuous form can be used to speak about a routine in the future:
I’ll have been typing for 6 days by tomorrow; we’ll have been using the YMCA showers for 9 months by February; I’ll have been studying Chinese for 8 months by April