The Future Perfect Continuous is normally used to predict the length of an activity — as if looking back at such activity from some finished time in the future.
The Future Perfect Continuous refers to ongoing events or actions that will continue up to some point in the future. It is most often used with a time expression.
- By July, Cindy will have been working in this office for a year (‘for a year’ is an imagined finished time in the future, but Cindy will still continue her work after it).
Here’s an illustration of what the Future Perfect Continuous (Progressive) expresses.
- I will have been waiting here for three hours by six o’clock.
- By 2001 I will have been living in London for sixteen years.
When to use Future Perfect Continuous
The Future Perfect Continuous tense is a combination of two English verb tenses: the Future Continuous (continuity of an action) and the Future Perfect (completion or result by a certain point in time).
An ongoing future event
Pattern 1: An ongoing future event in Future Perfect Continuous form may start in future and then only last for a set amount of time:
- By next November, I will have been working for that company for half a year.
The set amount of time in this sentence is ‘half a year.’ The action that has not yet occurred is working for the company. For example, the speaker may start working for that company in January and at the time this sentence is spoken, it has not yet occurred.
An event that have begun in the past
Pattern 2: Sometimes the event can actually have begun in the past, as in the case with our following example:
- You will have been studying for six straight months when you take the TOEFL exam.
In this example you have already started studying, but the act of studying for six months has not yet been completed. Once the exam is taken, this action will have been completed.
Future Perfect Continuous to show cause
Pattern 3: The Future Perfect Continuous is also used to show cause. This means that something in the future has not yet occurred but is likely to be the cause of another action that will also occur in the future.
- We’ll be in heavy debt because we will have been overspending for a month.
Future Perfect Continuous structure
To make the Future Perfect Continuous, use:
will have been + ‘-ing’ form of the verb (Present Participle)
|I will (’ll) have been doing|
You’ll have been doing
He/she/it’ll have been doing
|We’ll have been doing|
You’ll have been doing
They’ll have been doing
- By the time I arrive home, I will have been driving for six hours.
- By this time next month, I’ll have been studying English for a year.
- Melissa will have been cooking all day long before the wedding cake is ready.
Negative forms of Future Perfect Continuous
To make a negative form of Future Perfect Continuous, just insert ‘not‘ between ‘will’ and ‘have’ (you can also use ‘won’t’).
- I won’t have been eating vegetables for three years by then.
- They won’t have been playing since morning.
Questions inFuture Perfect Continuous
To ask a question in Future Perfect Continuous, just swap ‘will’ and the subject of the sentence:
will + [subject] + have being + -ing verb
- How long will you have been learning English by the end of this year?
- Will they have been eating cake for 15 minutes by the time you bring them coffee?
Here’s a video from Mad English TV with a good explanation of Future Perfect Continuous tense: