"The child jumps in the street."
Translation:아이가 길에서 뜁니다.
I was once told that 가 is used for observations of a specific thing while 는 was for more 'factual' statements. For example, if you saw a cheetah that was moving slowly, you'd use 가 to say "That cheetah is slow" But if you were to use 는 you'd be saying "Cheetahs are slow" which would typically be untrue. I hope this helps!