Would you take a look at the following sentences?
1) It has been raining hard since last night.
2) It has rained hard since last night.
Instead of 1) do you use 2)?
They are both correct- the progressive form just gives a bit more emphasis on the fact that it is still raining.
The same if true of 3&4, though when it comes to waiting, we almost always go for the progressive to stress our impatience.
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