The future perfect continuous tense, also known as future perfect progressive, is used to put an emphasis on the duration and progession of an action up to a certain time in the future. We also used it to talk about past actions from a future point in time.
Signal words for future perfect continuous used to refer to a specific time include next year, by this time, last week, etc.
Next year you will have been working here for 5 years.
Here, the future perfect continuous is used to emphasise the duration of the action (will have been working here for 5 years) up to a certain future time (next year).
Rule 1: To form the future perfect continuous tense, we use the same structure will + have + been + verb in the -ing form (present participle) for all persons.
Here is an overview of how to conjugate the future perfect continuous in positive, negative and interrogative sentences:
|I / you / we / they; he / she / it||I will have been playing.||He will not have been playing.||Will they been have playing?|
Note: In spoken and informal English, we can also use contractions in the future perfect continuous tense - a short combination of the verb will and particle not.
Here's an overview of contractions for the future perfect continuous tense:
|will not||'ll not / won't||they'll not / they won't|
Rule 2: We use the future perfect continuous tense to put an emphasis on the length of an action in progress at a certain time in the future (usually with reference to the duration of the action).
In an hour you will have been finishing your 24-hour movie marathon.
Here, the future perfect continuous is used to emphasise the length of the action in progress (will have been finishing) at a certain future time (in an hour) with reference to the duration of the action (24-hour movie marathon).
Rule 3: We use the future perfect continuous tense to describe what we imagine or think is happening at a certain time in the future or present.
The audience will have been waiting for hours for the show to start.
Here, we use future perfect continuous to talk about what we think is happening (will have been waiting) at a certain present time (for hours).
Rule 4: We use the future perfect continuous tense to express an assumption about what was happening at a certain time in the past.
It was pouring rain last night. People will have been hiding from it in the subway.
Here, we use future pefect continuous to experss an assumption about what was happening (people will have been hiding) at a certain past time (last night).
Complete the sentence. In half an hour she will have been ___ for 5 hours straight.