Difference between 는/은 and 이/가

In some situations, there is no difference in meaning or feel between adding ~이/가 or ~는/은 to the subject.

1. 그림이 벽에 있다. = The painting is on the wall. (This sentence simply states the location of the painting without any particular emphasis or comparison. It conveys a straightforward statement about the painting's location.)

2. 그림은 벽에 있다. = As for the painting, it is on the wall. (This sentence also conveys that the painting is on the wall, but it may imply a contrast or distinction with another object or context. It could be used to emphasize the painting's location in comparison to something else, such as a sculpture on a shelf or a photograph on a table. The use of 는/은 draws attention to the painting as the topic of discussion.)

In summary, both sentences indicate that the painting is on the wall. However, the use of 는/은 in the second sentence may introduce a sense of contrast or distinction, emphasizing the painting's location in relation to another object or context.