"It has been going on for hours."
Translation:Už to trvá hodiny.
I'm having trouble wrapping my head around how "už" works in this sentence. From "it takes hours" to "it's been going on for hours" seems like a very great leap. I'm not questioning the translation, I'm just trying to understand better. Are there other examples of "už" having a similar effect on the meaning of a sentence?
I try to think of "už" as "already". It usually helps, but not this time. "It's been going on for hours" is completely different from "It already takes hours".
(The latter implies that we are discussing a lengthy procedure and someone has suggested changing it in a way that would make it take even longer. The former is much more general.)
I would have to say that they are completely different.
"It's been going on for hours" states that a particular action started hours ago and is still happening right now. It doesn't indicate whether the action is by nature a lengthy one or a normally brief one that has been prolonged somehow.
"It already takes hours" is a statement about the nature of an action. It tells nothing about whether the action is happening now or how long ago it might have started (if it is happening at all).
In a hypothetical situation where both statements pertained, you would have to state both; neither one could be assumed from the other.