"A child spins a pencil."
Translation:아이는 연필을 돌려요.
I saw this in another post, but this is what I learned from it:
The suffix -가/-이 is used when you're talking about something specific. For example, when you want to describe the taste of a specific apple, you might say, "this apple tastes sweet", which would be: 이 사과가 달아요.
The suffix -은/-는 is used in a generalized scenario. For example, if you were describing the taste of all apples, you would say, "apples are sweet", which would be: 사과는 달아요.
Yup, but there's many more nuances to 가/는.
For example 는 can also be used to make a comparative statement.
사과는 달아요 The apple sweet, (compared to another apple we talked about before)
가 can also be used to indicate that the fact has been made due to a recent observation.
사과 달아요 The apple is sweet! (Based off the fact that I just took a bite)
So 가/는 can have many different nuances, and since we never know the context of these questions, both 아이가 and 아이는 should be possible.