It is used to express a continued or ongoing action that will start
in future and is thought to be continued till sometime in future.
(Remember, an ongoing action in future which will continue till some
time in future). There will be a time reference, such as “since 1980,
for three hours” from which the action will start in future and will
continue. A sense of time reference is found which gives an idea that
action will start at some time in future and will continue for some
time. Such time reference or sense of time reference is the identity
of Future perfect continuous tense because it tells that action will
start at a particular time in future. For example, “He will have been
studying in this school since 2005”, so the it means that he will start
studying in this school in 2005 and will study in this school till
sometime in future.
Note: If there is not time reference
or sense of time reference then it is not future perfect continuous
tense because there is no hint about the time of action when it will
start in future and it seems just an ongoing action in future which
resembles “future Continuous tense. So the reference of time
differentiates between Future perfect continuous tense between future
continuous tense.
Rules: An auxiliary verb “will have
been” is used in sentence. 1st form of verb (base verb) +ing (present
participle) is used as main verb in sentence. “Since” or “for” is used
before the “time reference” in sentence. If the time reference is
exactly known such as 1995, 4 O’clock then “since” is used before the
time in sentence. If the time reference is not exactly known such as
three hours, six years, four days, then “for” is used before the time
in sentence. Time reference such as 3 hours or 5 days is not exactly
known because we don’t know that about which three hours a day is told
in sentence or about which 5 days in a month is told in sentence. While
the 1995 is exactly know time.
Structure of sentence.
Positive Sentence.
• Subject + Auxiliary verb + main verb (Present participle) + Object + Time reference
•Subject + will have been + (1st form of verb or base verb + ing) + object + time reference
Examples.
I will have been waiting for him for one hour.
She will have been playing football since 2015.
Negative Sentence.
• Subject +”Not” inside Auxiliary verbs + main verb (present participle) + Object + Time reference
• Subject + will not have been + (1st form of verb or base verb + ing) + object + Time reference
To make negative sentence, the word “not” is added inside auxiliary verb, so it becomes “will not have been”.
Examples.
I will not have been waiting for him for one hour.
She will not have been playing football since 2015.
Interrogative Sentence.
• Auxiliary verb + Subject + auxiliary verb + main verb (present participle) + object + time reference
• Will + Subject + have been + (1st form of verb or base verb+ing) + object + time reference
Interrogative sentence starts with auxiliary verb “will” and auxiliary verb “have been” is used after subject in sentence.
Examples.
Will I have been waiting for him for one hour?
Will she have been playing football since 2015?
More examples.
Positive sentences
I will have been living in America since 2003.
He will have been playing cricket for two hours.
They will have been watching television since 6 O’clock.
She will been working in this office since 2007.
It will have been raining for three days.
Negative sentences
I will not have been living in America since 2003.
He will not have been playing cricket for two hours.
They will not have been watching television since 6 O’clock?
She will have been working in this office since 2007.
It will not have been raining for three days.
Positive sentences
Will I have been living in America since 2003?
Will he have been playing cricket for two hours.
Will they have been watching television since 6 O’clock?
Will she have been working in this office since 2007?
Will it have been raining for three days?
