Questions & Answers about Yağmur durunca sis oluşuyor.
-unca (or -ince after front vowels) is a temporal conjunctional suffix meaning “when,” “once,” or “after.” You attach it directly to the verb stem:
• dur- (stem of durmak, “to stop”) → dur-unca = “when it stops.”
It creates a subordinate clause describing the time frame for the main clause.
Both can express time, but with a slight nuance:
• durunca = “when/once it stops” (neutral, any time it stops)
• durur durmaz = “as soon as it stops” (emphasizes immediacy)
In our sentence, durunca simply states that fog forms whenever rain stops, without stressing an instant reaction.
In Turkish, durmak can be used with weather verbs to mean “to cease” or “to come to an end.” So:
• Yağmur durdu. = “The rain stopped.”
It’s a perfectly natural collocation, just like in English.