Are sometimes Simple Future and Future Progressive interchangeable

Question

One thing that tricks me is the meaning the progressive form of the future conveys. For instance:

This time next week we'll be meeting our boos

Saturday I'll be fighting him

Does those two mean:

Later in the future, We'll meet our boss and when this time next week comes, we'll still be doing so

Later, I'll fight him and when saturday comes, I'll still be doing so.

Or, does it mean:

This time next week we'll meet our boss

On Saturday I'll fight him

And the latter makes me question: if the latter is right, does it make both future forms interchangeable? How do they differ in meaning, and how is the future progressive different from its simple form? What's the usagage of the future continuous?

I'm really struggling on this.

Answer 1

The general rule is that you use Future Continuous when the action takes a certain amount of time, and you will be in the middle of it at that time:

At 5 o'clock, I'll be working on my project. (You'll start working earlier, and won't be done by 5'o clock).

This evening, I'll be plowing my fields. (You might start earlier, and you might not finish this evening).

Future Simple, in contrast, implies that the action will be done in the specified timeframe, or will start exactly at the given time:

At 5 o'clock, I'll work on my project. (You won't start until 5 o'clock).

This evening, I'll plow my fields. (You'll start and finish the same evening).

As with all general rules in English, however, there are exceptions. In this case, Future Continuous can sometimes be used where you'd normally use Future Simple - the grammar references I found refer to it as "future as a matter of course". In that sense, it expresses that the action is planned and will happen if everything goes well:

The government will be making a statement tonight. (Continuous, but it's implied that it'll start and finish during the same night)

But to use that structure, it should be obvious from the context that you don't mean the "regular" use of Future Continuous - otherwise you risk ambiguity.