"Het regent vier uur lang."
Translation:It rains for four hours.
Would Dutch accept "It's been raining for four hours" in place of "It rains for four hours"? In English "It rains..." doesn't seem to work except if modified by something like "It rains for four hours every day in this area." Does the Dutch sentence carry that connotation ? Also, does the progressive sense of "It's been raining for four hours" have another Dutch translation?
I also would like to know. The present continuous or simple present doesn't work in English except in an instance like you described, which requires more context ("... every day in this area").
By itself, I suppose this sentence would make sense in English if it has rained for two hours and I somehow know that it will stop raining after two more hours. If it started raining four hours ago and continues to rain now, it would be, "It has been raining for four hours," as you suggested.
Ronald, you are dead right in my opinion. In English, it is important to use present perfect to show it started raining four hours ago and that it is still raining and more especially present perfect continuous to lay emphasis on the duration