Translation:They want to eat within twenty-two minutes.
We say "They want to in 22 minutes" in English all the time. Yet the only correct answer is "within"?????
"They want to eat in 22 minutes." - "Chtějí jíst za dvacet dva minut." Hope this helped! :)
So, to clarify... with "za" we have "IN 22 minutes," while with "do" we have "WITHIN 22 minutes"? The difference is that, in the first case, they want to eat in exactly 22 minutes, but in the second case, they want to eat any time between now and 22 minutes from now? (Got it!)
Seems to me like a distinction with little difference. "I have to be at work in 10 minutes" does not preclude my arriving in 8.
Yes, you're right. But there IS a distinction made in the Czech sentences. I asked someone in a position to know, and this is the answer I received:
Chtějí jíst za 22 minut: If it is 11 a.m, they want to eat at 11:22.
Chtějí jíst do 22 minut: They want to eat at any time between 11 and 11:22.
Correct, but I think we should accept in here as it can mean do. I will add it.
Likewise you could say “eating in 22 minutes does not preclude them from eating before (too)”. But we should reasonably assume that they intend to eat only once, and that can be either in 22 minutes from now or within the next 22 minutes. That's the difference to your example, where being at work in 8 minutes does not interfere with being there in 10 minutes.
Thinking of za as “after” (instead of “in”) and of do as “until” (instead of “within”) may help you, though it does not yield a good English translation.