Future II progressive puts emphasis on the course / duration of an action taking place before a certain time in the future. It can also be used to express an assumption regarding a future action.
Future II progressive is not used very often as it can usually be replaced by future II simple.
Form
- A: He will have been talking.
- N: He will not have been talking.
- Q: Will he have been talking?
Use
- action taking place before a certain time in the future
- puts emphasis on the course of an action
Signal Words
- for …, the last couple of hours, all day long