We use...
... the future perfect to say that something will have been completed by a certain time in the future.
... future perfect continuous to say how long something will have continued by a certain time.
... future continuous to say that something will be going on at a certain time in the future. It can be used for planned or expected future events. In polite questions future continuous suggests „What have you decided?“, giving the idea that we are not trying to influence people.
... future perfect continuous to say how long something will have continued by a certain time.
... future continuous to say that something will be going on at a certain time in the future. It can be used for planned or expected future events. In polite questions future continuous suggests „What have you decided?“, giving the idea that we are not trying to influence people.