Sheesh.

I may actually be out of my depth here. But I do agree, it sounds pretty awkward to translate "Es wird regnen" to "It will rain." I mean, in German it's a simple statement, like you might encounter in a forecast, but in English it's more of a gloomy prophecy... Or maybe I'm imagining things. You kind of stare at subtle nuances for a while and stop seeing them.

In any case, I wish books like yours would stop with "this thing is barely used anymore" when it's actually alive and kicking... I mean, maybe they've counted and "werden" is in statistical decline, but if you ask any native speaker, no one is going to be surprised and not know what to do with it.

I would say, though, that often sentences with "will" in English might be better expressed in the present tense in German, and German sentences with "werden" - with "going to" in English. But it's a matter of nuance that can disappear if you stare at it too long. Except that it's kind of a translating standard, so you don't forget it that easily.

Yeah, I think that's my take on it. And it's really hard to think of examples that translate "will" to "werden", at least in a natural manner.