에 / 에서 / 로

Understanding these three particles is crucial for describing where things are and what happens where. They are not interchangeable.

1. -에: Static Location & Destination
This particle has two main uses:

• Static Location: Indicates where something or someone is. It's used with verbs of existence or state, like 있다 (to be), 없다 (to not be), 살다 (to live), and 많다 (to be many).
  Example: 책이 책상 위에 있어요. (The book is on the desk.)
• Destination: Indicates the destination of movement. It's used with verbs of movement like 가다 (to go), 오다 (to come), and 다니다 (to attend/commute).
  Example: 학교에 가요. (I'm going to school.)

2. -에서: Action Location & Origin
This particle also has two main uses:

• Action Location: Indicates where an action takes place. It's used with most action verbs.
  Example: 도서관에서 공부해요. (I study at the library.)
  This is the most common point of confusion with -에. If an action is happening, use -에서.
• Origin/Starting Point: Indicates where something or someone is coming from.
  Example: 미국에서 왔어요. (I came from the USA.)

3. -로: Direction & Means
This particle is more versatile:

• Direction: Indicates the general direction of movement, without specifying it as the final destination. It's often translated as 'toward' or 'to'.
  Example: 오른쪽으로 가세요. (Go to the right.)
  While you can say 학교에 가요 (going to school), you can also say 학교로 가요 (going toward school). The nuance is subtle, but -로 emphasizes direction over the final point.
• Means/Method: Indicates the tool, method, or transportation used.
  Example: 버스로 왔어요. (I came by bus.)