Future Perfect Continues
FORM
[WILL HAVE
BEEN]+ [VERB+ing]
EXAMPLES:
will have been waiting for two hours when her plane finally arrives.
USE 1 Duration Before Something in
the Future
We use the Future Perfect Continuous to show that something will continue up
until a particular event or time in the future. "For five minutes," "for two
weeks" and "since Friday" are all durations which can be used with the Future
Perfect Continuous. Notice that this is related to the Present Perfect
Continuous and the Past Perfect Continuous, however the duration stops in the
future.
EXAMPLES:
They will have been talking for over an hour by the time Tony arrives.
She is going to have been working at that company for three years when it
finally closes.
James will have been teaching at the University for more than a year by the
time he leaves for Asia.
USE 2 Cause of Something in the
Future
Using the Future Perfect Continuous before another action in the future is a
good way to show cause and effect.
EXAMPLES:
Jason will be tired when he gets home because he will have been jogging
for over an hour.
Claudia's English will be perfect when she returns to Germany because she is
going to have been studying English in the United States for over
two years.
IMPORTANT No Future in Time Clauses
Like all future forms, the Simple Future cannot be used in clauses beginning
with "when", "while", "before", "after", "by the time," "as soon as," "if" and
"unless."
EXAMPLES:
I won't tell the student the answer until he has been working on
the math problem for more than an hour. Correct
I won't tell the student the answer until he will have been working
on the math problem for more than an hour. Not Correct
