The future continuous tense, sometimes also referred to as the future progressive tense, is a verb tense that indicates that something will occur in the future and continue for an expected length of time. It is formed using the construction will + be + the present participle (the root verb + -ing).
The simple future tense is a verb tense that is used when an action is expected to occur in the future and be completed. For example, let’s suppose you have a meeting tomorrow at five o’clock.
I will arrive is the simple future tense of the verb to arrive. You arrive once; beyond that, you can’t keep on arriving. However, once you get there, you may be doing something that goes on continuously, at least for a certain period of time.
Will be meeting is the future continuous tense of the verb to meet. The construction will + be + the present participle meeting indicates that the meeting isn’t going to happen in an instant, all at once. It will have a duration. The will + be + present participle construction always indicates the future continuous tense.
The Future Continuous Tense Is for Action Verbs Only
It is important to note that the future continuous tense is only used with action verbs, because it is possible to do them for a duration. (Action verbs describe activities like running, thinking, and seeing. Stative verbs describe states of existence, like being, seeming, and knowing.) To use the will + be + present participle construction with a stative verb would sound very odd indeed.
As you can see, only the simple future tense is suited to stative verbs like to be and to seem.