Questions & Answers about כשיש חושך בחדר, הוא מדליק אור קטן ליד המיטה.
כשיש is made of כש־ + יש.
- כש־ means when
- יש means there is / there are
So כשיש means when there is...
In this sentence, it introduces a situation: when there is darkness in the room...
Hebrew often expresses this idea with יש + a noun.
- יש חושך = literally there is darkness
- Natural English would usually say it is dark
So the Hebrew structure is a little different from English, even though the meaning is the same.
A very common alternative in Hebrew would be:
- כשהחדר חשוך = when the room is dark
Both are natural, but כשיש חושך focuses on the presence of darkness.