Particle indicating direction, means, or cause
When to use
direction of movement, means, cause of something
The nuance
Use ‘으로’ to indicate direction, means, or cause; if the noun ends without a final consonant, use ‘로’.
으로 (eu-ro, euro) · 에 (e)
‘으로’ indicates direction or means, while ‘에’ marks destination or location.

One lane per word — no nested boxes, just the gist.
Particle indicating direction, means, or cause
When to use
direction of movement, means, cause of something
The nuance
Use ‘으로’ to indicate direction, means, or cause; if the noun ends without a final consonant, use ‘로’.
Particle indicating destination, location, or time
When to use
destination, location, time
The nuance
Use ‘에’ to indicate destination, location, or specific time.
학교로 갑니다.
hak-gyo-ro gap-ni-da., hak gyo ro gap ni da.
‘학교’ indicates direction of movement, so ‘으로’ is correct.
학교에 갑니다.
hak-gyo-e gap-ni-da., hak gyo e gap ni da.
‘학교’ is a destination, so ‘에’ is also correct.
버스로 갑니다.
beo-seu-ro gap-ni-da., beo seu ro gap ni da.
‘버스’ is the means of transport, so ‘로’ is correct.
버스에 갑니다.
beo-seu-e gap-ni-da., beo seu e gap ni da.
‘버스’ is the means, not a destination, so ‘에’ is awkward here.
집으로 돌아갑니다.
jip-eu-ro dol-a-gap-ni-da., jip eu ro dol a gap ni da.
‘집’ shows direction, so ‘으로’ is correct.
집에 돌아갑니다.
jip-e dol-a-gap-ni-da., jip e dol a gap ni da.
‘집’ is a destination, so ‘에’ is also acceptable.
책상으로 앉습니다.
chaek-sang-eu-ro an-seup-ni-da., chaek sang eu ro an seup ni da.
‘책상’ is a location, not a direction, so ‘으로’ is inappropriate.
책상에 앉습니다.
chaek-sang-e an-seup-ni-da., chaek sang e an seup ni da.
‘책상’ indicates location, so ‘에’ is correct.
Which particle fits with ‘버스’?
Correct particle for going to ‘학교’?
Correct particle when sitting on ‘책상’?