"That building is big."
Translation:저 건물이 큽니다.
It's a topic particle, basically signifies that you're speaking about a specific building rather than just any generic one.
So when I use 는 after 저 it means a I and when I don't use it, it means that?
이것=this 거것=that 저것=that over there...am I wrong? Why are they not using the 것.
것 means thing or object and 이 means this. So rather than saying "this object" 이것, they are saying this building.
When do I use 저 or 그? Or what's the difference between the two? Cause i thought the latter means "that" too... Thanks!
Korean has three different demonstrative categories while English really only has two, which can make it harder to understand the difference. 이 is close to the speaker (this), 그 is close to the listener (that) and 저 is far from both of them (that over there).