studiousbees:

-(으)로 is a very useful particle that can be attached to nouns (both normal nouns and nouns created using noun modifier endings) for a variety of usages. Especially at the beginning, it can be a bit hard or confusing to differentiate these different meanings. Let’s take a look at some of the most common usages of -(으)로!

Please note that -으로 is used when the preceding noun ends with a consonant except ㄹ, and -로 is used when the noun ends with a vowel or ㄹ.

Also, please note that there is another usage of -으로 that, when used with an adjective ending with -적, creates adverbs. However, I want to keep this post focused on -(으)로 on its own and write a separate post for adverb formation.

By means of

You can use -(으)로 to express using something for a purpose. In this case, we can think of the particle as meaning “by (means of)” or “using.”

버스로 갔어요. (I went by bus.)

연필로 쓰세요. (Write using a pencil.)

Toward

Another usage of -(으)로 is indicating the direction in which someone or something is moving. Please be careful not to confuse it with the destination particle -에! While they can at times occur in the same position, -(으)로 places more emphasis on the direction of movement or the actual process of going rather than the destination. As they do not mean the same thing, they are not interchangeable. 

이쪽으로 오세요. (Come this way.)

어디로 가는 거예요? (Where are you going?)

Selection

When choosing between two or more things, you can use -(으)로 to indicate your choice or selection.

그것으로 살게요. (I’ll buy that one.)

민지 씨가 추천해준 식당으로 할까요? (Should we go to/choose the restaurant that Minji recommended?)

하얀색이면 너무 쉽게 더러워질 거예요. 검은색으로 하겠어요. (If it’s white it will get dirty too easily. I’ll choose black.) 

Change

When you want to express that something turned into or became something else, you can use -(으)로. When used this way, there is a feeling of emphasis on the difference between the start and the end result. 

말썽꾸러기였던 정원 씨는 진지한 사람으로 변했어요. (Jeongwon, who was a troublemaker, became a serious person.)

보수적인 윤혁 씨는 개방적인 친구들하고 놀다 보니까 개방적인 사람으로 됐어요. (Conservative Yunhyeok became more liberal through hanging out with his liberal friends.)

(Acting) as

The last usage of -(으)로 I will cover here is used to indicate the position from which someone is speaking or doing an action.

그 웹사이트에 회원으로 가입했어요. (I registered for that website [as a member].)

선생님으로 일하는 게 가끔은 어려워요. (Sometimes working as a teacher is hard.)

-(으)로 is a very common and useful particle. Make sure you practice all of its usages so you can recognize and use them all productively!

As always, happy studying~